If in case you have missed the news or didn't get it as yet then WPF/E is now called Silverlight. Yeah! Its kinda a kewl name.
Few weeks back Microsoft at MIX07 made a number of announcements and showed off Silverlight. Silverlight is a cross-browser, cross-platform run-time that enables media and interactive content and application scenarios or say its a browser independent version of the Windows Presentation Foundation (WPF). Silverlight currently supports IE6, IE7, Firefox and Safari browsers on both Windows and the Mac and is installed by a single click installation that takes only couple of seconds.
Microsoft Silverlight 1.0 Beta is now available for download including a Go Live license which means Microsoft customers can deploy their Silverlight applications.
Here couple of links that I'd recommend to check...