I just want them to re-release Pac-Man VS. That's one of the greatest party games ever, and would be easy to do with the Wii-U setup. Think there's some interesting things that could be done with the screen in the controller, but I have a bad feeling most developers will be doing "access your inventory/map" stuff. Heard Ubisoft's Rayman game for it was pretty intriguing though.
Nintendo is actually bringing their Wii U Experience tour to Austin this Saturday, and I'm signed up to go to it. I'll give my impressions of it after that. But what I really want from the system is for them to drop the exclusivity of Rayman Legends.
I was always a Nintendo guy. N64 was their last best with the Gamecube being a close contender. Everything Wii has just sucked horribly mainly due to their forcing us to play with shitty motion controls.