Project Origami: Could This Be It? - Updated!

"Microsoft demoed it at WinHEC 2005. While I was there, I had the opportunity to interview a woman on the MobilePC team, where she showed off the prototype device that Bill had onstage." More info and pictures here. The device seems to run at a 6 or 7 inches diagonial screen, at 1024x600 widescreen resolution.