I've been holding off on buying the Wii U, mostly because it didn't really seem different than the Wii.
And that is the problem. To me the Wii U isn't that different. It feels like a Wii with updated graphics for the HD crowd(welcome to 2007 Nintendo). So far I am not impressed. The controller has a very limited battery life 3-4 hours, so I'm constantly recharging it. You can plug it into an outlet without the worry of battery life diminishing, but you have to be plugged into a frikkin outlet to use the controller. No problem, I'll just buy another one so I'll have one charging while using the other. Oh that's right they aren't available to purchase individually??
I bought it for one reason: Super Mario Brothers U! I love the Mario games, and 2-D Mario is great except....It feels so close to the New Super Mario Brothers for the Wii that it could almost be the same game. Same game engine, and few tweaks here, and there. Different levels, better graphics for sure, but the music is much of the same(seriously they couldn't change the dungeon music?).
Sorry about the rant, but It is my own fault for being an early adopter. Talk to me next year with the new Mario Cart, and Zelda, and I'll probably be singing an entirely different tune.