Just released is a sample app from Scott Stanfield (RD in San Francisco) and his company Vertigo. As presented on Tim Sneath's blog, this is a sample that shows how to deal with video presentation using all the new tools and Silverlight - almost like a Soapbox or YouTube experience. The source is located on CodePlex.
Tim has a large write-up about the intent of this sample, as well as eluding to the announcement last week on our S+S Blueprints.
Side Note: As you'll remember, Scott and his Vertigo team built another reference application called Family.Show, which showed how to use WPF in a family tree scenario. It's well done too.