I talked about this a bit in my news piece recently (
http://www.techrepublic.com/blog/programming-and-development/windows-8-native-apps-and-html5-facts-and-conjecture/4313). The details are hazy, but it looks like Windows 8 is now pushing an HTML5-based application system pretty hard. The details will be announced at the BUILD event, so there's a lot of speculation, but looking at the Windows 8 plans, it may be critical for developers (especially of tablet apps) to be familiar with, like WPF is now.
J.Ja