This is one for the developers. The Microsoft Software + Services Blueprint folks have been kind enough to build a blueprint for the use of Silverlight in SharePoint Web Parts. The Silverlight Blueprint for SharePoint is source code and guidance for developers describing how to use Microsoft Silverlight and Microsoft SharePoint Products and Technologies together in business applications and Internet web sites. SharePoint applications that use Web Parts can now be built using Silverlight user interface elements. This capability enables a fresh look at data exposed through SharePoint Products and Technologies using the modern graphics capability in Silverlight.
For more information about samples that we’ve built that you can reuse, customize, or extend for your SharePoint web sites and for links to downloads and screencasts click here to go to the Silverlight Blueprint for SharePoint page on MSDN.