The PS3 itself has barely sold 3x more than Bioshock, what on earth are you babbling about.
I agree that the use of 10's has been a bit liberal (it seems like no one's willing to use the ol' 9.5 these days except for Orange Box), but the fact of the matter is it's been an amazing couple of months for games, and Mario Galaxy, Mass Effect, Ratchet, and Crysis are still to come. I really do think that the games that have received them thus far have been that much better than the rest of the field this generation. A few tenths of a point here and there doesn't change that.
As long as there are only a handful of titles that average over 90 each year on gamerankings per platform, I think that reviewers are doing a good job of protecting us from crap and letting us know what rocks.