I have been playing around VSTS 2010 / TFS 2010 / .NET 4.0 CTP features for a while. It's available for download at the MSDN site in a VPC format with Windows 2008 server as the host. This VPC provides a few sample TFS projects and a few VSTS 2010 solutions as well.
There are a lot of cool features which make the architecturing process much easier using VSTS 2010 / UML 2.1 elements for Requirement Analysis, the associated Use Case realizations and translation of design into implementation. Feature for calculating code metrics has been enabled too as in VSTS 2008.
You can find the following templates and the associated tool box elements for modeling :
A few reference URLs:
http://blogs.msdn.com/camerons/
http://blogs.msdn.com/camerons/archive/2008/09/30/vsts-2010-and-net-4-0.aspx
http://blogs.msdn.com/camerons/archive/2008/06/25/dsl-uml-pragmatic-modeling.aspx
Visual Studio 2010 and .NET Framework 4.0 Overview
http://msdn.microsoft.com/en-us/vs2008/products/cc948977.aspx
Creating a Project Template for "The 4+1 View Model of Software Architecture"