Speaking at CES 2010, Kaz Hirai announced that the Sony PlayStation 3 sold 3.8 million units worldwide in the month of December. 1.7 million units were sold in the US alone, which would be up over a million from last year at the same time. The PS3 sold close to 500K in Japan, meaning that close to 1.6 million consoles were also sold in Europe as well. Hirai cited titles like Assassin's Creed 2, Modern Warfare 2, Uncharted 2, and Final Fantasy XIII as key drivers of the PlayStation hardware.
Nintendo announced earlier this week that they moved 3 million Wii consoles during the same period. We'll have a better picture of what Sony sold next Thursday, when the official NPD numbers hit(which, by the way, Sony and Nintendo have done a great job of spoiling).