It's nice to see this app make the light of day. I saw it a few months ago. InfusionDev did a great job in building the original version of this app in WPF, and now it's been ported to Sliverlight 2 beta... It really does a great job in helping people visualize the practical, corporate possibilities that wpf and silverlight bring to bear.
Check out the app right now, if you have Silverlight 2 installed. If you need to know where to get Silverlight 2, jump to http://www.microsoft.com/silverlight/resources/installationFiles.aspx?v=2.0 .
Jaime Rodriguez has a great posting on this, that talks about the background on the demo app, and includes a link to the source code.