On Tim Sneath's blog he has announced that "WPF/E" or Windows Presentation Foundation Everywhere is now called Microsoft Silverlight. This is the typical renaming from a "code name" to a "product name" and not much more but now we know what it will be called. You can read the announcement from Tim at http://blogs.msdn.com/tims/archive/2007/04/15/introducing-microsoft-silverlight.aspx. The official (although not yet really functional site) is at http://www.silverlight.net/ and more information is available at http://www.microsoft.com/silverlight and the press release is at http://www.microsoft.com/presspass/press/2007/apr07/04-15WPFEPR.mspx.
I saw David Yack demonstrate this at the Code Camp on Saturday. It looks like it is very easy to embed rich content into web pages and also to code against that object model.
I am really curious what the big announcement that Tim alludes to in his #10 item on his blog post. Now I can hardly wait for MIX. Only 2 weeks and counting.