Wii 2/HD will be a better comparison, because that will be a system coming off the market leading predecessor and third parties will take the system much more seriously from day 1.
The Wii will get better, but it's really not a fair comparison versus the PS2.
For what its worth I think Super Mario Galaxy is better than any game on the PS2 (then again it's probably the best game Nintendo has released in ages themselves).







