Thanks Linkzmax. Very informative. I think it is only fair to adjust region launches to coincide. Also it should be noted that PS2 lauched for ~$100 (adjusted for inflation) more than the Wii, so that works in favor of the Wii. It will definitely be interesting to see if the Wii can finish this gen ahead of the over 140 mil the PS2 currently has.
Though, one does also have to admit that this gen, the market is bigger than it was last gen. The Wii may pull off that 140 mill, while never going past the 50% marketshare point. And the Gamecube, or X-Box for that matter, never reached 33.5 mil shipped (where PS3 sits now, even though we have at least 2 more years of this gen to go).