This service pack (Visual Studio 2005 Service Pack 1 Beta and Team Foundation) includes both fixes and new features. For those who want line item detail of what was fixed for Team Foundation Server in SP1 Beta, you should go read Brian Harry's latest post (Bug fixes in TFS SP1). When reviewing this list, understand that there were some items that didn't meet the bar for a variety of reasons (e.g., unable to repro, by design behavior, too wickedly hard to fix in time for this SP, etc.).
Historically, we (DevDiv) haven't released detailed information about what bugs we fix in various releases. At some level it's one of those things that has been around long enough people don't even wonder why any more. I can speculate that it's partially because it's too much work to pull the information together. I'm sure there's a little bit of fear of the "How could you have possibly shipped with that bug" or "... that many bugs" response. It's hard to put bugs in perspective and it's hard to explain in a reasonable way and without a lot of effort all of the conditions that must be in place before a bug is hit.
From: Bug fixes in TFS SP1