This is worth a look.
A simple plugin to Expression Encoder that makes it trivially easy to publish your encoded content to the Silverlight Streaming service. This wasn't that hard to do manually before, but it was a bit fiddly. Now its a simple question of completing the following dialog.
Your encoded content will be uploaded with the created manifest, and it will generate the iframe code you will need to include on your web page. In addition you get to see existing streaming applications you have created, see the iframe code, preview it, and delete it. Now we just need Microsoft to change that rather crude 22MB limit for video files to something more meaningful.
Get it from here
Cheers
Ian