Nintendo showed a version of Tekken for Wii U during its press E3 press conference earlier today. But Nintendo gamers may not have to wait until Wii U's 2012 release to get some Tekken. Namco Bandai is also readying a 3DS Tekken game.
Regarding the 3DS version, Namco Bandai promised to make use of the system's 3D capabilities to add intensity to the experience. Neither version has a set release date or price.
You can see a clip of Tekken (and all the other third party Wii U titles) in this montage: