Unisys has graciously lent us a great 8 way machine to test out how TFS handles substantial loads (ie the entire developer division). Brian Harry's blog has all the data about how using performance tests we see we can scale to over 3500 people on the dual server implementation using the ES7000/600. We are working w/ Unisys to procure one of these machines to run the entire developer division's next version of engineering on top of TFS. that will be exciting!
Check out Brian's blog for the details.