Microsoft originally released this back in June, but pulled it because of a few issues. These have been corrected and it's back!

You should apply this update to the TFS application server, build machines, proxies, and TFS SharePoint portal servers (if you have a multi-tier dpeloyment). Pretty much anywhere the TFS SKU has been installed. SP1 is a pre-requisite and is not included.
Download from http://www.microsoft.com/download/en/details.aspx?id=26211
Details about the update: http://support.microsoft.com/kb/2536929

In the consulting world, we are always adding new external resources to our trusted domain that need to be included in TFS workflows. (Client technical resources, accounts for contractors both on and offshore, product owners, etc) Waiting for TFS to re-sync its list of users can be painful.

Neno Loje has a new blog post and tool to force this sync to occur on demand. In the past I've usually just re-added the domain group these users are members of to the Team Project, but this tool is a much cleaner solution.

If you're stuck using VS2005 for some projects, the forward compatibility update for accessing and using TFS 2010 is now out.

The VS2008 update has been out for a while.

Getting a TF270015: 'MSTest.exe' returned an unexpected exit code. Expected '0'; actual '1' error trying to build a VS2008 project in TFS 2010?

Make sure you have installed the Team Explorer 2008 bits on your build server. You may need to run a Repair on the TFS 2010 on the build server after this because it will drop an older version of Microsoft.TeamFoundation.Build.targets in the MSBuild folder.

I'm adding this to my 2010 build server checklist.

I'm at PDC09 this week in LA. I'm looking forward to playing with the new VS 2010 and TFS 2010 features, and taking a peek at Azure. If you're @PDC and follow my blog, drop me a line.

Today at 1:30EST, watch Sara Ford of CodePlex and VS Power Toys fame show off some cool Visual Studio tricks and tip.

I've been testing this hotfix for about a week, and it has cured a good chunk of my usual VS2008 crashes. Specifically, if you undock any windows withing the IDE, or change the layout, VX2008 tests to crash the next time you enter debug mode. I tend to change my layout a lot when I switch between working on C# mid-tier code, and into Data Dude to work on data generation configuration, so this one hit me a lot!

Download the hotfix here: KB960075