I think the Wii U will trend well, but under the Wii in its first two and a half years, and then trend ahead of the Wii in its next three and a half years and end up with comparable numbers by the end of year 6: around 100 million units.
Nintendo has heavy third party support unseen on a home console since the SNES era, and never this much in the launch window before. They have room to drop their major bombs later on in the console's life stream rather than early on like the Wii. I think the push ahead will come about year 3, Nintendo always releases some sort of "it" title - on the NES it was Mario 3, SNES was DKC, N64 was Goldeneye 007 and Ocarina of Time, and on the Wii it was Mario Galaxy. Only this time on the Wii U Nintendo is a far larger company than it used to be.
On the 3DS front, I think it will do exceptionally well, but it won't hit the same levels as DS, but really it's early to tell, it has no true competition except its own price point and ability to create demand.
PS4, Vita, and Xbox Loopty-loop - I think these consoles are going to be a harder sale than the Wii U if they're just going to be some sort of an incremental upgrade to existing platforms.
As has been happening with handhelds, I think in the home console arena, Nintendo is going to increase their market dominance.
I describe myself as a little dose of toxic masculinity.
