http://blogs.msdn.com/e7/archive/2009/03/25/touching-windows-7.aspx
The engineering Windows 7 blog has done another great post! This time on the Windows Touch elements and what was done to improve Windows w/ regards to touch and multi-touch UX as well as why. The most interesting part of the blog post to me was the information about the telemetry they reported during the beta (how often particular touch features, like scrolling content, were used and how successful people were w/ particular touch features.)
Very cool from an engineering perspective as well as a user perspective