Ballmer just announced this at the Consumer Electronics Show keynote today.
looks like a follow up on what Patrick reported a couple months ago.
Here's the relevant bit of the update via Barron's, for those who care
...We’re getting a demo of using the “Kinect” controller to interact with episodes of Sesame Street. The young assistant on stage demonstrates using a throwing gesture to help out Grover by “throwing” a coconut that appears to land in Grover’s box of coconuts I the episode playing on screen.
Ballmer announces Kinect will be coming to Windows on February 1st.
And that’s pretty much it. I closing, Seacrest asked Ballmer what he thought the future would bring. Ballmer, in a spoof of his legendary boisterous style, remarked “Metro, Metro, Metro,” referring to the name for the Windows 8 user interface. Then he added, “Windows! Windows! Windows!