Someone on the newsgroups asked for an official answer on why Team System is not in Whidbey Beta 1. The short answer is that it's not beta quality, so it didn't belong in a beta. Keep your eyes open for another CTP release in the next few months. The current plans for this upcoming CTP are for it to include the server portions of Team System that were not in the May release.
And about the re-posting of the May CTP:
The May 2004 CTP that contained Team System (but not Team Foundation, which includes source control and work item tracking) is supposed to be up on MSDN by Monday. There were a number of requests for it in the newsgroups after it was mistakenly removed from MSDN.