Post removed at user's request.
Some gotchas with video in this release:--It requires Windows Media Player 10 be installed on the machine.--It only plays .wma and .wmv files.--It requires the latest video drivers for most video cards. (For sure on ATI Radeon 9600/9700, which is what I have.)
--There is little documentation.
Here's a simple file you can put into XAMLPad to see it working:<Grid xmlns="http://schemas.microsoft.com/winfx/avalon/2005" >
<MediaElement Name="myVideo" Source="C:\WINDOWS\system32\oobe\images\intro.wmv" Stretch="Fill" />