Windows Phone Developer Tools CTP refresh available! This build is compatible with Visual Studio 2010 RTM! For those who are in Silverlight development – from now it is possible to develop Silverlight 4 applications with Silverlight 4 RTW and Windows Phone 7 applications with this CTP refresh.
The download location here.
Make sure you are reading what’s new document here and Release Notes (from download location). Additional information about changes could be found here.