Update 20th July 2010: There is now a Hotfix from Microsoft that resolves this issue, see http://support.microsoft.com/kb/2252691; thanks for the pointer Daniel.
If you’re developing BizTalk projects and using TFS 2010, you’ll probably need to install Team Explorer 2010 to leverage some of the new functionality not accessible through the Visual Studio 2008 TFS hooks. Team Explorer 2010 is a stripped down version of the Visual Studio 2010 environment used solely to access Team Foundation Server services.
Be aware that if you do install Team Explorer 2010, you’ll nark your Enterprise Single Sign-On installation, meaning you can’t make any changes to BizTalk – when ESSO attempts to start, you’ll probably receive the following error in the Application Event Log:
Could not create SSOSQL. To fix the problem, reinstall SSO or try 'regasm SSOSQL.dll' from a Visual Studio command prompt.
Error Code: 0x80131700
regasm "C:\Program Files\Common Files\Enterprise Single Sign-On\SSOSQL.dll"