If you try to install the Team Foundation 2008 SharePoint extensions on a 64bit farm you get a ‘SharePoint must be installed’ error; I guess the installer is looking in the wrong directory for something to confirm SharePoint is there.

However, it seems the MSI is only installing some features that are not 32/64bit specific. So you can try a manual install of these features.

The notes on http://msdn2.microsoft.com/en-us/teamsystem/aa718901.aspx give a basic guide, but these were written for the previous SharePoint so you have to alter a few paths, mostly 6.0 to 12.0 in the paths to the Web Server Extensions EXEs, and the templates have moved in Team System to [Program Files]Microsoft Visual Studio 2008 Team Foundation ServerToolsTemplates

This lack of 64bit support is really starting to become a pain!