I think it'll definitely do better than the Wii U at least. I'm thinking by the end of its lifetime it could at least do 3DS numbers. Wii numbers seem out of reach though imo.
Nintendo has several good things going for it that makes the switch in a better position than the Wii U.
-It's a portable and a home console. So Nintendo can consolidate their first party efforts. and it'll have access to franchises that were staples of one type of system, like Pokemon.
-It has no competition. The switch is a handheld first and a console second. People keep comparing this to the PS4/XBO when it should be compared to the 3DS/Vita both of which are on their death beds. Which pretty much gives the switch free reign over the audiences of both platforms. Plus the devs of both of those will probably navigate over to the switch.
-It's on ARM instead of X86, which may help in keeping exclusives since unlike PS4/XBO/PC devs actually have to put in some effort to port games.
-it's under powered, which I see as a blessing in disguise. Less dev time is needed so we'll be able to see faster turn around rates for games. Also devs who may be intimidated in creating a big budget AAA PS4/XBO game may find their niche in the more leveled playing field the Switch offers.
Of course it's Nintendo so of course they have to scrub it up in some ways tho...
-Their conference didn't inspire much confidence tbh. It felt like they learned nothing from the Wii U and are still chasing after the WII golden era AKA an audience that's never coming back,
-Weak launch line up and pricy. Not launching with a Pokemon or MH seems like a big mistake. Pokemon I can understand since S/M just launched and it's still selling well, but they totally should've foot the bill for Capcom to release a new MH game for the switches' launch. Or at least had a trailer or something to show.
-Paid online. I don't think this will benefit the Switch as much as you guys think. Paid online is mainly a western thing and I think Switches biggest strength will be in Japan who aren't really used to it. The biggest platforms there are PS3,3DS,Vita, and Mobile. All of which offer free online. There's the PS4 but that's not really selling super well there yet. Also I don't think the value is really worth it. Looking back at the Wii U/3DS very little games actually took advantage of online anyways. So with Nintendo's lackluster offerings/ few games to take advantage of it I think it might backfire on them. The only way I could see it being some type of a success is if it was like 10-20 dollars. If it's 50-60 like PS4/XBO then they can go fuck themselves.
Overall here's what I see as the road map which'll be very similar to the DS/3DS
-It'll sell out at launch due to a combination of, it being a new console/Nintendo's artificial scarcity
-It'll have a rough first year due to being expensive/lack of content
-it'll do ok around the holidays due to sales/bundles
-A year after launch Nintendo will announce either a price cut/revision. The library will become much more solid, and thus the console will hit its stride and take off.