MikeB-
DMC3 as someone stated earlier only sold 300k Lifetime on the PS2 which is 4 times bigger than the Wii's.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut