Nintendo's detailed a prototype for Wii U, Super Mario Mii.

You can also take the action away from the TV and play it on the Wii U controller, the NOA boss confirmed.
The game's also set to feature a multiplayer mode which has one player using the Wii U controller, and three more using Wii Remotes in a hide-and-seek type scenario.
"What I've just described are prototypes, not just actual games."