At long last (and before Mix!) we've finally announced the name of WPF/E: SilverLight. Read more about it
here (
http://www.microsoft.com/silverlight/). This is a good thing because, frankly, the confusion has already begun to set in about the differences in WPF and WPF/E. Not only is the name cool, but finally there's some distinction between these two products.
If you're going to Mix, be sure to check out demos from Jeff Prosise and also from members of the SilverLight team.