Leon just posted a new tool he developed called "TFS Permission Manager" for managing Team Foundation Server permissions in an easier fashion. Way to go!
Here are some benefits in the tool:
"Using this tool you can:
- Add or remove TFS group membership, Reporting Services role membership and SharePoint role membership
- Set Server and Project-level permissions
- Set AreaPath and Source Control permissions
- Create new TFS users with permissions identical to those of specified existing user
- Save user permissions as template and use it later to create new or update existing users. "