Allow TFS Admin to choose AD usernames or AD Display names.
Team Explorer uses AD display names and Source Control uses AD usernames. Different organizations have different needs, let each administrator decide how they want users represented and make it consistent throughout TFS. For example I'd like TFS to use AD usernames everywhere, this would allow easier synchronization with other tools (HPQC for one).
Ralph Daigle commented
We just went through an AD name change (rescheme) it took some extra nudging to get Team Server to work and have our projects pick up where they left off. This idea may have helped!