Hi Chris Bond,
We are considering adding support for 4.0 for 3.7 version. The next SP is scheduled after the middle of July, because we are waiting for Q2 release of the RadControls for ASP.NET AJAX.
When you run a project in VS2010 you do not have to upgrade the project to .NET Framework 4.0 which is currently not supported.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items.