We'll see if Mario can do what WSR + Monster Hunter Tri + Jet Black Wii combined couldn't do ... get the Wii out of its Japanese doldrums.
I have some doubts that one game alone can do it as well. And it better be a great game, not just a good game.
The stakes are very high for that game.
I think relative to its userbase, Final Fantasy will see a surge on the PS3 because it's the first installment of the franchise with next-generation HD graphics. Much like MGS4 did not sell all that much less than MGS3 in Japan despite the PS3 having a much smaller userbase at that time. I think Famitsu is low balling with their estimates. If MGS4 can sell 700k+, I think FF13, a much bigger franchise coming out at a time where the PS3 is in much better shape can do 2 million+ and move a ton of those FF13 White PS3 bundles with it.
I feel the PS3 will beat the Wii during the main late December-early January holiday push in Japan (which is the biggest sales period of the year), probably by a decent margin at that. They are obviously going to rout Nintendo in September thanks to the PS3 Slim.