The numbers are in for September, and according to videogame-tracking concern VGChartz, the 360 has outsold the PlayStation 3 and the Wii.
Microsoft sold 520,698 consoles during the month, compared with 496,591 Wiis sold and 168,393 PS3 units. If you guessed this is because of Halo, you're right--the third game in the shooter series put the 360 over the edge in sales, selling 3,196,516 copies since its release.
The biggest selling console of the month, though, was the Nintendo DS. That system sold 620, 910 times.