Nintendo tends to innovate every other generation.
NES - their first console
SNES - better version of NES
N64 - Analog, rumble, 3D
GCN - better version of N64
Wii - motion controls (and motion control plus!)
My guess is the next console will be a SuperWii, which means more refinement than innovation. At the same time, MS and Sony will ape the Wii, and likely will avoid the mistake of another bleeding edge, very expensive console.
Each company therefore will likely start on a relatively equal footing console wise. Success will be determined by 1) brand loyalty (edge for NIntendo there), 2) marketing, and 3) quality of games and motion controls/new inputs.







