Wii U, according to a song licensing arrangement spotted by GoNintendo. Independent music publisher and licensor Royalty Network states that the song "Evacuate the Dance Floor" was requested for use in a game titled Your Shape Wii U.
Given that Your Shape is already available on the Wii, it's not too surprising to see it heading to Wii U. Our only concern is how the Wiipad will be able to support our body weight. And you can forget about multiplayer.