I would hazzard a guess that the POTENTIAL market for a cartoony platformer is a lot larger than any single very specific (albeit large) sports market
IE LBP could still be selling consistantly after Fifa10 or 11 has been released
(ok may still not make #1 but could outsell 09 in time)
Are you talking about FIFA '09 sales purely on the PS3?
Even so I still think it will outsell LBP, even way down the line.