It really doesn't make sense (that X360 would be still ahead) when you look at shipments for whole year.
X360 by quarters: 1.3 million, 1 million, 1.2 million, 3.5 million = 7 million
PS3 by quarters: 3.4 million (this still had PS2?), 1.1 million, 2 million, 3.3 - 3.5 million = 9.8 - 10 million