Two chief problems with the Wii U: the touch screen controller was derided by hardcore gamers as unnecessary and uncomfortable (even without actually, you know, playing with it first). And with the Wii U supporting only one tablet controller per system, multiplayer would have been a pain.
Nintendo addressed both those problems in style. Behold the Wii U Controller Pro.
It will be sold separately, and it will be compatible with all Wii U games. No other details, such as price, were provided.