The thing is, Wii U hardware is very outdated, and it is not even released yet. It is here to compete with this generation of consoles, not the next. And when next-gen comes, Wii U will be screwed.
I even doubt it doing well now, before the actual next generation. My guess would be, that once the initial "wow, a new console" will end, and the hardcore Nintendo fans will have bought this, it won't even sell as much as PS3 or 360 anymore. (Assuming it costs more than the other two) Especially since most big (Not Nintendo) games will still be multiplatform, (I doubt we would see 100 million dollar exclusive to Wii U) making even less of a reason to get a Wii U.
And it seems like many people simply can't imagine what could be achieved with "actually new" hardware, and greatly underestimate what could be done with an Xbox 720 or Playstation 4. The jump to next Playstation and Xbox, will be just as significant as from PS2 to PS3.
Comparing PS3/360 to Wii U is like comparing PS2 to first Xbox, there is the slight edge, but nothing significant, and it will be simply blown away by Xbox 720 and Playstation 4!
(To me it seems) all the factors are against the Wii U succeeding...
PS. Wii U hardware IS last generation!
