In this article, they use vgchartz numbers for MW2 (360).
"Let's use Call of Duty: Modern Warfare 2's numbers as an example. According to data from VGChartz, 4,890,348 discs sold of Xbox 360 version alone in the first week."
starcraft: "I and every PS3 fanboy alive are waiting for Versus more than FFXIII.
Me since the games were revealed, the fanboys since E3."
Skeeuk: "playstation 3 is the ultimate in gaming acceleration"