Microsoft CEO Steve Ballmer will tease Windows at the Microsoft Keynote at CES later today, according to a report. Ballmer will make a number of announcements regarding Windows Phone 7, Xbox and Windows. The main announcement will reportedly center on a version of Windows that will run on ARM microarchitecture, as has been rumoredin recent days. Sources familiar with the matter are also predicting that Ballmer will demo a new feature of Windows 8 for the first time.