I just started playing around with the Silverlight Streaming and this is my first try at posting a video clip. I used Expression Encoder to encode the clip, used a pre-installed template, and then posted my job. Very easy. Expression Encoder is included with Expression Media, or you can just download a trial to play around. Accounts for streaming on Live are also free.

Took me a moment to figure out the iFrame size, but got that sorted I think.