It would be better than the Wii console because it doesn't use a controller. A camera detects motions and tells the game what to do.
I presume it has already been invented but hasn't been picked up by Nintendo or Sony Playstation, etc.
Some other developers have been working to make existing game consoles to be more like a Wii. Like in the video below called "Halo Motion Sensitive Gaming with the Mad Genius Motion Capture System".
However that is not what I am looking for. I am looking for a "pure motion capture" system using cameras. No hand held devices needed.