In conjunction with the units sold to date, over 40 million user accounts have been created on Xbox Live. No numbers were released on how many such accounts were tied to one unit or what percentage were Gold Memberships.

The Kinect sensor also had a successful 2011. Observers of the gaming industry have seen Microsoft heavily invest in the Kinect over the past year, and it has clearly paid off. Despite the dominance of the Nintendo Wii and the recent introduction of the Sony Move, the Kinect has sold over 18 million Kinect sensors in little over a year. With the continued push of the motion controller device, including the requirement that all future Xbox 360 apps offer Kinect support, Microsoft is attempting to make the device an essential part of the Xbox 360 (and perhaps the Xbox 720) experience.

In celebration of these milestones, Microsoft released the following video showing the successes of both the Xbox 360 and Kinect in 2011:

httpv://www.youtube.com/watch?v=bhoFMNcpYwo&list=UUjBp_7RuDBUYbd1LegWEJ8g&index=1&feature=plcp

Ballmer also confirmed that the Kinect will soon no longer just be limited to the Xbox 360, but will now be officially supported by Windows 7 and Windows 8 on February 1, 2012. Unfortunately, it appears that the Xbox 360 Kinect Sensor will not be supported. Instead, users will need to purchase a Windows-compatible Kinect sensor for $249.99, which will only work with computers running the Kinect for Windows SDK software.

What do you think of these numbers? Should Microsoft continue to focus on the Xbox 360 and Kinect as its primary platforms rather than turning its attention to the Xbox 720?