There is a recent Visual Studio extension called “Silverlight Sharepoint Web Parts” which has simplified the work of the “Sharelight” or “Silverpoint” developers. They can now embed a Silverlight application in a site page of Sharepoint in a rapid and efficient manner.
More details in my articles on silverlightshow.net:
Silverlight and Sharepoint working together: the Silverlight SharePoint Web Parts - part 1
Silverlight and Sharepoint working together: the Silverlight SharePoint Web Parts - part 2