Apparently I was too late with my fps vs rts idea since Ubisoft is already making that game with Killer Freaks.
My jaw literally dropped when I read your idea, so I'm also glad to hear that they're doing it with Killer Freaks and hoping that there is a robust online mode.
There are some good ideas in here and hopefully since the best idea imho is already being done, a lot of others here are as well.
How about off the TV ideas? With BnM's mention of RPG management, it occurred to me that switching a game like that onto the controller only, would have to feature an entirely new UI combining what was on the TV and the controller since they are both vital to the game. If every game is going to switchable to the controller, it would make somethings like the shuriken throwing demo a lot easier (since the target would have to appear on the screen), and things like MGS (if using Kytim's idea for the camera application) a lot harder.
Then there's the potential for controller only games, like that game of Othello that they showed. Could that be broadcast to the TV so that even though two people are playing chess, their drunk friends can stand around making funny comments without breathing down their necks? (This happened to me last night btw, and I lost...).
Just because of how much potential there is (and 3rd party support) I'm becoming a big believer in the WiiU. I just wish the controller screen was multitouch because I had an idea for an adventure RPG were you moved/attacked/magicked all with screen by having eight fingers on it, and different motions and combinations of fingers on the screen performed different actions. Complicated for sure, but something I would personally love if done right.