Since Q2 2010 all new functionalities are listed in the control's Release Notes posted
Added CDN support - you can load the controls scripts and skins from the Telerik CDN.
Register the resource Handler in the web.config automatically when RadScriptManager is put on the page
RadScriptManager can be put at the end of the page and still support partial views
The controls now have an OutputCompression property to control the gzip/deflate compression of the combined output