A lot of great information about the roadmap for Visual Studio Team System future releases has been posted at Visual Studio Team System Future Releases . If you're interested in what's coming soon in "Orcas" and after that in "Rosario", check this out.
This is great information to consider as you are planning your adoption, mapping out deployment, or even evaluating specific functionality.
Also included in the list are more details on power tools...
Link to Visual Studio Team System - Future Releases