The ability to look around and move at the same time, now possible thanks to the Motion Sensing Wii Remote by Nintendo (with optional Nunchuck attachment - sold seperately), could do wonders for any game played in first person. Before you know it people will be emulating it by adding look functionality to a second analog stick, a hardware feature that has been available for a while now but never used to this creative degree.
In all seriousness, I'd probably want it if I had a Wii. The lacking controls (which have sort of become a common theme for me) are what kept me from finishing Metroid Prime, or giving a shit about any other Metroid game since.