John Papa announces that he and his team have recently added a new demo and updated 2 of their more popular Silverlight demos to use Silverlight 4 RTW.
The Silverlight.net samples web site has all of the samples, but here are direct links to each of the demos with a brief description of them and the features they showcase. These demos are great and parts of them are from contributions from several people at Microsoft including Karen Corby, Adam Kinney, Mark Rideout, Jesse Bishop and from me.