Basically, if this is an honest-from-MS statement, they've just admitted that:
(A) Killzone 2 looks better than any 360 title on the shelves, and..
(B) They haven't even announced a title that will look better, let alone shipped one. I.E. They are saying that the PS3 will have the best looking exclusive shooter for... more than a year at this point? At least until the holidays, and frankly... MS doesn't announce a game and then just drop it on the shelves the same year, from what I can tell.
Given that, I don't believe MS would make such a statement at all. They don't foot-in-mouth that badly. (B) may be true no matter what happens, but only if MS were to admit to (A), would it matter, from a PR standpoint. They are not going to admit to (A), since its not some hard fact that KZ2 "looks better" than all other console shooters. Its just a commonly held opinion.