The holidays are traditionally a good time for hardware/software sales, and with the Wii still in short supply, it was up to the PS3 and X360 to pick up the slack. Today, Microsoft revealed that it has sold more than 17.7 million X360 units worldwide, while Halo 3 breaks records with no less than 8.1 million copies sold since its Sept. 2007 launch. In little over a month, Mass Effect has already sold 1.6 mill. units, and according to November NPD data, consumers keep spending money on Xbox software and accessories, with a record-high attach rate of 6.9.