First of all, when considering Madden sales, you need only take into account the North American userbase since it has negligible sales in Japan or Europe.
That said, I think it will be very close between PS2 and 360, probably with PS2 taking the top number by a hair. I also think it will be close between Wii and PS3, probably with Wii having a decent advantage. I'd wager the PSP version will outsell the Wii and PS3 versions but be well behind the top two.
In Memoriam RVW Jr.
SSBB Friend Code = 5455-9050-8670 (PM me if you add so I can add you!)
Tetris Party Friend Code = 116129046416 (ditto)