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.
Rick LaPlante personally replied to the post with the following answer.
While Paul provides a skeptical, yet possible explanation, as I made the decision, I'll tell you what the real logic was.
CTPs (community technology previews) are about getting bits out regularly to customers for early feedback and discussion. With this release of VS, we are trying to be more open about what we are building and give earlier access to folks to the bits. By definition, these bits are basically stable builds from our own source trees with minimal additional quality checks built into the process. They are <NOT> beta quality. they are interim builds. As such, it was appropriate to put parts of the Team System into the CTP because we met the quality bar and certainly needed to start getting feedback asap about the feature set and implementation. As Paul correctly points out (and we've said many times) the Team System is not currently at beta quality and as such we did not include it in Beta 1 of VS. We will have another CTP in the next few months based on the VS Beta 1 bits that will include the Team System (again not a beta quality build, but expected to be much better than the May CTP) and then follow on with VS Beta 2 which will contain a full, beta quality version of the Team System.
Hope this answers your question.