A leaked Rayman Legends trailer sprung up today showing some of the first footage of a Wii U in use. About halfway through the trailer, we see one player using the touch screen on the Wii U controller to manipulate objects in the game while others are playing. This is fairly disappointing as you have one player watching other players play the game. However, the trailer concludes with a very interesting feature of the Wii U controller that hasn't been seen before.
What appears to be a toy heart is placed on the Wii U controller screen and then appears in game. Then they use a similar Rabbid toy resulting in the Rabbid appearing in game, and then concluding that a Ezio, from Assassin's Creed, figurine could be used next. This is reminiscent of Skylanders' use of pad that allows toys to be scanned and appear in the game. So either the Wii U controller has a touch screen that can also scan images or the toy is giving off a signal that the Wii U controller can receive. Interesting stuff from Nintendo, and I'm sure more info will be coming from them at E3.