Well, yeah, the 360 is the only "mature" console of the three, meaning it has the best game selection(most recently Gears of War) and no supply shortages. That would explain the recent sales. Really though, I think the train wreck of the PS3's launch is what sold the most 360s.
At this point I honestly think the PS3 is going to flop. Sony has thrown away the two big advantages that made the PS2 what it is - the cheap price and the huge library of exclusives. The PS3 will never be affordable like the PS2 is, and already most of their biggest exclusives(GTA4, Assassin's Creed, etc) are coming to the 360. They got cocky and drastically overestimated the power of their name brand, and it cost them big. Now that they've lost the faith of both the consumers and their developers, I'm really not seeing what they can do to get themselves out of this one.