The Wii sold over 100 million consoles and was their best selling home console and it lasted 6 years but the final year was not supported much, so their best system by far was supported 5 years. The last real support the Wii had from Nintendo was LOZ SS in 2011 a full year before the Wii U launched. It was pretty much abandonded in spite of having the largest user base since PS2.
Not sure how anyone can believe that we will see 3 more years of support on a console with so little demand. We can expect a Legend of Zelda game, Fire Emblem crossover, Yarn Yoshi, and maybe another Mario title/sport spinoff (there have been 2 and a DLC retail release already in the first year). Pikmin, Wario and DK are done this gen for Wii U, Kirby, Star Fox, and F Zero are unlikely on Wii U, Wii series is probably done, and a Metroid is probably not going to give the Wii U a boost, maybe a 3DS title. What's left? Maybe a new IP or 2 a year or more from now?
At this point, anything left for the Wii U will be announced this E3. We know third party games are few and far between and any that they do get will be on other consoles as well. I can see next year being the last year of support by Nintendo with a successor releasing by fall 2016 latest without a doubt, with major support running out by holiday 2015, and anything still be worked on hitting in early 2016. 2012-2016 seems to be long enough to save face and early enough to keep investors from jumping.
So far all year we only had Lego Movie and DKC. For the year, so far we can expect.
Mario Kart 8
Smash Bros.( which is also on the 3DS, so anyone who really wants just that and has a 3DS will just get that version) Bayonetta 2
Amazing Spider-Man 2 (multi console)
Sonic Boom
Transformers (multi console)
Watchdogs (multi console, delayed on wii u, might be cancelled)
X
Hyrule Warriors
Project Cars (multi console)
And a handful of downloadable titles that don't scream buy a Wii U
LOZ and Yarn Yoshi have no solid release date and could easily be delayed until next year. It seems like Nintendo is already slowing support if you can count. We might see a few more third party titles release this year but it's doubtful that any new announced games from Nintendo will release this year. We could literally see 15-20 retail games release for a whole year for Wii U. I may be missing a few titles, but there are whole months this first half a year with literally 1-3 retail games total for the Wii U, do people really think there are so many games in development that we don't know about and will suddenly explode onto it?
Edit: And looking at the NA releast years of Nintendo consoles, we had...
NES 1985-----SNES 1991-----N64 1996------Gamecube 2001------Wii 2006-------Wii U 2012 you almost see a pattern here where the years end in a 1 or 6, on average Nintendo only supports their consoles about 5 years almost consistantly, but with the poor state of the Wii U, I think they will end this a little sooner.
