Don't get me wrong The Wii U still looks pretty intriguing. I think Nintendo realized before everyone else that consoles won't be around forever, so they're doing the best they can to make consoles a unique experience that a PC or iPhone can't imitate.
Stylus controls and tilt sensors were really unique when Nintendo first introduced them for their handhelds but now the iPhone can do that stuff too, so now they're banking on the 3D thing. And now that 360 and PS3 are ripping off the WiiMote Nintendo are wisely trying something different.
People can hate on Nintendo night and day for whatever dumb reasons they like but I think they're the guys keeping the console industry fresh right now, because they're thinking like a true video game company. Sony and Microsoft are not true video game companies, they're multimedia businesses, and they approach video games just like every other branch of media they're involved in.
Because of that their future in the hardware industry is more assured. Nintendo are the ones who have to take more risks if they want to stay in the game.
However the novelty of cool new control styles can't last forever and once all of Nintendo's ideas become industry standards they will eventually run out of tricks.
I hate to say it but I see Nintendo going the way of Sega in becoming an exclusively software based company at some point in the future.

But that might not be all bad. It could make for some awesome crossover games. I'd love to see Mario beat the everloving shit out of Master Chief myself.