I just finished up the keynote at VSLive in Vegas. I did an update of my Building Amazing Business Applications with Silverlight 3 talk from Mix09. I updated to the latest internal builds of Silverlight 3 and .NET RIA Services late last week for this demo. It was very fun to see stuff come together an improve. There are some great updates to the Navigation Application template, navigation in general, authentication, master-details databinding, dataform and much more that makes this demo even more smooth.
I will do a blog post with all the code as soon as Silverlight 3 RTMs.