I nuked my machines to move up to a clean build of Windows 7 RTM. In rebuilding them I hit a snag with the XNA3.1 install. The install would start and then rollback just after the redistributables copy started.
To overcome this issue I set the runtime compatibility of the XNA 3.1 install file to be Windows Vista Service Pack 2 – you do this from the file property dialog. Re-running the XNA 3.1 install it all worked fine.
On starting VS2008 Pro I see that I have both XNA 3.0 and XNA 3.1 project templates available.
A quick test building the platform game and everything looks good.
Now I just need a Zune HD!