Davide Zordan posted a quick overview and reference to a sample chapter from the new book of Gastón C. Hillar: “Microsoft Silverlight 4 and SharePoint 2010 Integration”
This is the overview taken from the publisher site:
Develop Silverlight RIAs that interact with
SharePoint 2010 data and services
Explore the diverse alternatives for hosting
a Silverlight RIA in a SharePoint 2010 Page
Work with the new SharePoint Silverlight
Client Object Model to interact with elements in a SharePoint Site
Use Visual Studio 2010′s new features to
debug Silverlight RIAs that interact with SharePoint 2010