And here's the promised follow-up: basically outlining the Switch's current situation in the same cathegories used to describe the Wii's.
Hardware sales
In the same way we can't comment way too negatively on potential third party support for Switch since it's three months old, we can't start thinking that its hardware sales will certainly go beyond 3DS' heights. However, we can say that hardware numbers so far are good and that's in spite of major shortages affecting its potential especially since May. Also, thanks to Nintendo's current first party slate, there shouldn't be too many doubts on the system's potential in the mid-term (unless one / two of the biggest games surprisingly fail to live to expectations, of course). As the productions speeds up, shortages should become less and less problematic. Hopefully, that process is moving at a good pace. Overall, the mid-term sales potential is pretty good, which represents a major difference compared to Wii U, PSV and PS4 (PS4 strictly in Japan, the other two on a worldwide scale).
HW sales so far have been positive, no doubts. We don't know the higher ceiling, because of shortages, but we know Japan is interested in the concept. I was pessimistic against initial hw sales too and I was wrong. But my latest posts are concerned about how long the interest can last, if the hw will be sustained only by "Nintendo usual output" (quantity-wise, without an actual merge of their development streams), and so the comment about the concerning third party support.
Software sales/support
Of course, the current third party support cannot be considered "good" on a general level, because it isn't: there are upcoming releases not coming to the system, companies still missing, not too much quantity-wise. Still, there are some good signs for the future, even in this early stage: KT and Square being so upfront and releasing so many titles on the system already, stuff like Fate/Extella and Nights of Azure 2 appearing, some pretty good results already (Bomberman, Puyo Puyo Tetris, Seiken Densetsu Collection - I'd even include DQHI-II on a lower scale, since it's still selling in spite of its high MSRP) with no major discounting in sight (quite unusual compared to most recent hardware launches). Also, as I've said multiple times, Japanese companies tend to be slow to bring their games to new hardware. Moreover, while both 3DS and Vita saw over 60 retail games released in their respective first years, it can be said that the vast majority of those games (especially for the latter) were not that relevant at all. And I'd also dare to say that looking at 3DS's retail releases highlights how different the industry is now: it was a time when digital storefronts weren't nearly as big as they are right now, and 3DS didn't even release with its own eShop. This means that it's possible a good chunk of initial 3DS games would've been digital-only releases. The same, but on a lower scale due to its later release, can be said for Vita.
Nirolak also noted how 3DS started getting a more convinced push from third parties around 9 months after its launch, while Vita/PS4 had to wait a bit more (12-to-18 months) to see releases finally rolling at a regular pace. Personally, given the current worldwide hardware/software success, I think we could see the more important push happening more on the lower side of the 12-to-18 months gap. We'll have to see how things go, but I'm feeling quite confident that to say that a successful platform in all regions shouldn't have problems to see third parties starting releasing their own content on it with a more regular pace. And I know what you're going to say, "The Wii was in the same situation, but the push happened too late". Actually, the situation isn't that similar...
Sorry but here I disagree. There are too many assumptions (so far has been like that but I think that probably...), too many mistery games, too many NDAs and so on.
3DS and PS4 werent' similar at all, because what shows confidence in a console in Japan are also the announcements, not only the actual releases. Both consoles cited had SEVERAL games announced for the console, before/during their respective unveil. Japanese timings of development and actual support are slow, but the main difference is that the software houses simply weren't developing games for Switch, while they already were for 3DS and PS4. If 3DS and PS4 had to wait 9/12 months to start seeing those actual already planned games coming to the console, Switch will have to wait way longer than that. Especially because we should have noted, by now, how software houses AREN'T ANNOUNCING Switch game yet. So, if we look back at 3DS and PS4 and we see how they were more than ready to announce games for those console to confirm support way before the release of those games, we should assume that they aren't developing games and the few under development will start hitting the console way after the 9/12 months seen for 3DS/PS4. And this is exaclty the concern: they weren't developing, they saw initial hw sales, they are evaluating and not yet on board (otherwise we should have already seen significant announcements) and thus if HW sales will continue to go well they will probably start developing something, that will arrive very late in the life cycle.
At a point where HS sales could have already start seeing a decline in their pace, if they must be sustained only by the usual Nintendo output.
The market's context
This is probably what I consider the biggest difference between the Wii and the Switch, for several reasons.
First of all, the Wii came out when Nintendo's own handheld, the DS, was already selling at unpredecented levels, while the PSP was going to see a resurgance in 2007 starting with Monster Hunter Portable 2nd. This is certainly not what's going on right now: the Switch has been released in a time when the 3DS, while still selling and while still kept alive by Nintendo, is far from its glory days; while the Vita (a mediocre success on its own) is rapidly slowing down, with small weekly numbers. Remember how the Wii became, after its first (strong) months, the third best selling system in Japan? The Switch will be the best selling platform in Japan for quite a while, especially once the shortages lessen their hold on the console's sales potential.
It seems that you are ignoring two major factors:
Mobile
PS4 worldwide success
If anything, those two main scenarios are collecting the DS/3DS dust way more than Switch. Nintendo itself so far isn't pushing the Switch as a true successor of the 3DS, trying to keep the 3DS relevant. Mobile is the new "DS", while it is obvious how with PS4 they can have two separated but unique platform where to develop for to find a global success. Back in the Wii days, it wasn't like that, and the Wii was a very attractive platform for a new, wide range of potential targe/sales.
Second, Wii and PS3/360 were extremely different development environments, due to engines / effects / power support's difference between the two, and (a few) Japanese developers who tried to chase success on the Western side of the market couldn't easily adapt their own tech and games for the Wii: more resources and employee were required in order to port PS3/360 games to Wii, if not to create a specific version for the system (maybe running on its own engine). While Switch is less powerful than PS4/Xbox One, the difference isn't nearly as large as the one between Wii and PS3/360 and (even more important) the current major engines / effects are pretty well supported. This means that ports from PS4 and Xbox One are far easier and far cheaper (and this is why we've heard KT having good words about their multiplatform engine on Switch.
This is true: Switch development "asset" is better than the Wii one, comparatevely to the landscape. Still, we are seeing many software houses struggling to shine on it (from Unity to UE4, optimization is not that easy to achieve, apparently). So of course there are less barriers, but there still are barriers, hw-wise.
Moreover, the system seems to be an healthy environment for third party games of different kinds: Bomberman, Puyo Puyo Tetris and Seiken Densetsu Collection have seen good if not great sales given what they represent, while DQHI-II is a fine result for now. Not everything sold even just well (Ultra Street Fighter II is quite low for now, even if given the title we're talking about I don't believe Capcom is THAT unhappy about it), but the current worldwide (so, not just in Japan) situation represents a system enjoying a healthy software environment, both retail and digital (the Arcade Collection over 200,000 units as of a few weeks ago is another demonstration). Certainly, it has to be demonstrated how this is going to translate as more and "corer" games come to the platform, but, again, some good signs already.
C'mon: the only actual success so far has been Bomberman: the best selling episode in more than a decade, on track to become the best selling episode of all time for the franchise (or something like that). This is a significant result, one that could actually move resources internally in Konami toward the Switch. The others? Not that much. We can argue that DQH i-II is decent for what it is, but could this result move something inside SE toward the Switch? Not more than what they are already planning, imho. And yes, they are among the best supporters of the console, not denying that. But can other companies look at DQH I-II sales and evaluate to change their development plan, allocating resources to the Switch moving them away from other streams? I don't see why they should. Of course, the initial support was poor, so we actually have few examples/champèions, but this is often the issue with third parties on Nintendo platforms...
It's also a good thing that the current first party lineup is not just strong, but interestingly quite steady and laser-focused. I'll try to explain myself better. This is the Japanese first year lineup by Nintendo on Wii, including release dates
The Legend of Zelda: Twilight Princess {2006.12.02}
WarioWare: Smooth Moves {2006.12.02}
Wii Sports {2006.12.02}
Wii Play {2006.12.02}
Pokemon Battle Revolution {2006.12.14}
Excite Truck {2007.01.18}
Fire Emblem: Radiant Dawn {2007.02.22}
Eyeshield 21: Field no Saikyou Senshi Tachi {2007.03.08}
Super Paper Mario {2007.04.19}
Big Brain Academy: Wii Degree {2007.04.26}
Donkey Kong Barrel Blast {2007.06.28}
Mario Party 8 {2007.07.26}
Endless Ocean {2007.08.02}
Mario Strikers Charged {2007.09.20}
Super Mario Galaxy {2007.11.1}
Mario & Sonic at the Olympic Games {2007.11.22}
Wii Fit {2007.12.1}
A lot of games (17), with several major sellers, but also smaller titles; now, that wouldn't be a bad thing, but it becomes a problem when there's a significant gap between important releases. This is exactly what happened between Mario Party 8 and Super Mario Galaxy, around 3 months with no major game in-between. And that's exactly when the Wii started losing its own momentum in Japan, with sales rapidly declining after Obon.
Let's look at the current retail Switch lineup, instead
The Legend of Zelda: Breath of the Wild {2017.03.03}
1-2 Switch {2017.03.03}
Mario Kart 8 Deluxe {2017.04.28}
Arms {2017.06.16}
Splatoon 2 {2017.07.21}
Pokken Tournament 2 {2017.09.22}
Super Mario Odyssey {2017.10.27}
Xenoblade Chronicles 2 - Fall 2017
Even if it's not a completely balanced comparison (since we're comparing both lineups up to the consoles' first non-launch Holiday, several more months are included for Wii), it's clear that Switch still has a lower amount of first party retail games, especially if you exclude Fire Emblem Warriors due to its special status of being a third party game in Japan. But as I've already said, it's more "laser-focused", in the sense that the vast majority of this year's releases are good / great games that can all help to carry on the console's momentum, with Xenoblade Chronicles 2 as potentially the lowest selling game among them.
First party lineup so far has been well managed. Good choice to allocate timings, good marketing push and so on. Good product selection too. In fact they are carrying the console in a very good way.
Quantity-wise we are not at the same Wii level you posted, despite Wii U ports and multiplatform games, so my question still stand: how will they manage to support the console if now, exploiting Wii U ports and multiplatform developed delayed games, they aren't able to retail as many products as in the initial Wii era? This is where my concern about them ditching so far the advantages of the hybrid console hits.
Certainly, there's a distinct lack of specifically casual-oriented games outside of 1-2 Switch, which pales in comparison with Wii Sports / Wii Play / Wii Fit, three major first year's tentpoles. Not that Zelda, Mario Kart, Splatoon and Mario are completely unattractive to less informed gamers (especially Splatoon 2, IMHO), but Wii had titles strictly targeted for that kind of customers, and we'll have to see whether Nintendo will start releasing that kind of software (even if in different forms) on Switch again. This could also be a sign of a different approach to the installed base expansion, potentially more traditional: trying to bring early on more core customers, while also releasing major bridge franchises, and then later, as the hardware price decreases, expanding towards less informed customers. This can help third party games as well in Japan.
You brought up another big concern, without solving it.
Casual market represented the vst majority of Wii sales, but now that blue oecan segment has shifted to mobile. I wonder how they could fill the potential gap with the wider market without being able to target that crowd. Nothing so far can make us believe they will actually be able, also looking at the decrease the 3DS suffered compared to the DS era.
It's also interesting to see how there seems to be a specific plan that implies specific gaps (still much smaller than what seen on Wii) in the lineup to let other important third party games the possibility to shine: Minecraft in May, MHXX in August. That's potentially changing in Japan in September, when both Fire Emblem Warriors and Pokken will be released; it still stands how this time the lack of major first party games is actually supplemented by specific third party releases - or better, how it seems it's not a random coincidence of schedules.
If third party games aren't even announced, I can't see how they could properly fit a release schedule. I prefer to not base my analysis of ghots games.
The last major difference in market contexts between Switch and Wii is that PS4 is in a different condition than PS3 back then. Wii and PS3 both released at the end of 2006, and we all know how the latter had major problems in selling on a worldwide scale, and incredible problems at attracting enough Japanese third party support due to different factors (difficult development environment for Japanese developers, DS/PSP gaining further market shares, even the Wii itself, and Microsoft didn't help either due to their several Japanese-focused partnerships - yep, the last generation is an interesting beast). So, slow growth, and 2009 was when things started improving considerably. Meanwhile, the Switch has been released at a time when the PS4 is established in the market, with already several major games released for, as well as upcoming major titles (DQXI, MHW, DW9). It's also true that PS4 is still seeing less-than-ideal sales for a market leader in Japan (I mean, it's still trending not that far from PS3 - but, again, DQXI will surely help in the short-term) while being the biggest platform in Europe and US, and this creates an interesting scenario where the system could be chosen by Japanese developers for potential Asian / Western sales prospects compared to Japanese's.
Sorry, but PS3 VS PS4 situation just confirm my concerns. It is clear how PS4 could well be seen (and actually is) as an healthy worldwide platform, opposed to a suffering PS3. Even with very solid sales, in fact, Switch could still be seen as a secondary choice, due to PS4 record-breaking success, while the Wii at a certain point could have be seen as THE choice, with its outstanding success. So, Switch situation is even harder.
And that's it for my Switch/Wii cross-analysis. It came out...probably longer than what I wanted. Sorry to everyone XD