That's why Natal will be used exclusively only for games like the Wii motion is used exclusively. As I said a few times already, the other games like the ones you mentioned, even on the wii, rely mostly on buttons and analog movement with very little actual motion controls.
So a 360 controller for those games and Natal for the other games is perfect. And perhaps some integration like with the SixAxis.
And since Natal is about a good 8-12 months away, why don't we wait and see some more developed games to see if this can be used in other ways besides just the Wii stationary type games.










