With regards to "hardcore" games: Third parties have had this wrong from the beginning, and continue to get it wrong. When the Castlevania fighting game and Soul Calibur action game failed, that should have been the clue that sticking a known property into a different genre from usual was a bad idea. But instead, Resident Evil Darkside Chronicles and Dead Space Extraction.
Speaking of Dead Space Extraction, after the obvious consumer dissatisfaction from the reveal that it was a rails-shoo... "guided first-person experience" they should have went back to the drawing board with the game. This commonly happens with HD games (see Splinter Cell Conviction and I Am Alive), so why not with a Wii game? Let's continue talking about DSE, since it is an interesting case study. It got good reviews and was a quality game, so why didn't it sell? Well, let's not kid ourselves, it got decent reviews; it's not like it's getting the kind of universal acclaim Mass Effect 2 is. And you know what; quality is only one of three factors that is needed for a successful game. The other two are concept and marketing. With regards to Wii games, I think Tatsunoko vs. Capcom has been the first third party Wii game to get TV advertisement since the Sega trio, so DSE clearly fails that metric.
Concept is in my opinion the metric that is most important, and at the same time is the metric that most third party Wii games fail spectacularly. The fan backlash against DSE and RE Darkside Chronicles was immense, showing that the consumers clearly didn't care for their core concepts. And if they don't care for the core concept, no amount of advertising or quality will be able to win them over.
For example, I give you a conversation I had with one of my friends (paraphrased):
Friend: "Man, I can't wait for Dead Space Wii to come out."
Me: "It's out already; I have it." (marketing fail)
Friend: "Really? Is it good?"
Me: "Yeah, I enjoyed it."
Friend: "Sweet I'm going to go get it."
Me: "... You know it's a rails shooter right?"
Friend: "It is? Screw that." (concept fail)
I believe this is the reason why the Call of Duty ports, and even the Conduit which is mediocre in quality, have sold better than DSE and RE Darkside Chronicles, because the core concepts were appealing. Coincidentally, Call of Duty was an HD game first, and the Conduit was designed in an attempt to ape pretty much everything from modern HD FPS games.
Conclusion 1: If the core concept of your "hardcore" game wouldn't fly on PS3 and 360, don't bother making it for the Wii.
Conclusion 2: A well-done HD port to the Wii is safer than a ground-up game. (emphasis on well-done)
With regards to "casual" games: On Pach-Attack you had said that the casual bubble had burst. I disagree. It has only burst for third party casual games. Nintendo's more casual games (Wii Fit Plus, Wii Sports Resort, etc) are still performing very well. Two things here:
1) Annualized sequels for casual games don't work. Someone on this board and I can't find the original post and don't remember who said it so I apologize for not properly attributing this said that the "casual" audience goes for concept sequels rather than content sequels. This is why Guitar Hero World Tour outsold Guitar Hero 5; World Tour added significantly to the core concept (the full band) while GH5 just added some modes and new songs.
2) The "casual" audience has wised up. In a way I feel worse for the "casual" Wii owners than the "core" ones; if the "core" Wii owners are second class citizens then "casual" Wii owners may as well be homeless beggars. Third parties assumed that "casuals" were both naive and stupid, and as such gave them terrible games and, when they sold well, terrible sequels to said games. Unfortunately for them the "casuals" were not stupid, so they learned after playing said terrible games that the games were, indeed, terrible, and that the sequel should be avoided. A good example of this would be the Japanese release (I know we are talking US NPD but bear with me) of Deca Sports 2, which had an astounding 3% opening sell-through. Ouch.
Conclusion 1: Do not release a sequel to a casual game until the core concept is improved upon, like Wii Sports to Wii Sports Resort (more precise controls)
Conclusion 2: Treat the "casuals" as serious consumers, and you shall be rewarded. Examples: EA Active (excluding more workouts, see Conclusion 1) and Tiger Woods 10.
edit: minor grammar