Right after the official release of Silverlight 4 Release Candidate, Telerik has prepared for you
a native build of RadControls for Silverlight that are built on the latest platform’s release.
We will keep on updating the files with each Latest Internal Build. The RadControls for Silverlight 4 RC is still a preview version of RadControls for Silverlight 4 that will become official as soon as Microsoft announces the RTW version of Silverlight 4.