The comparison is a bit unfair since they put both Uncharted games in there for PS3, but only one of each L4D and Gears of War.
It's also a scandal that Fable II is missing for the X360.
With these adjustments the quality would be very close.
Anyway, after this year the X360 could become the king of the game libraries again by adding
Halo: Reach, Mass Effect 2, Fable III, Alan Wake, Splinter Cell Conviction, Metro 2033, Crackdown 2 and Kingdom Under Fire II.