As I hear about issues people run across installing VSTS Web Access, I'll post here guidance to help you be successful.

1) VSTS Web Access (like TFS 2008) does not currently support running under 64-bit.  Our recommendation is that you install it on a 32-bit system.  I'm told that you actually can get it to work on a 64-bit system by, after installing it, going to the IIS manager, openning the app pool, clicking "advanced settings", clicking "Enable 32-Bit Applications, and then recycling the app pool.  I haven't tried this myself so you'll be a bit on untrodden ground if you decide to go this way.

2) VSTS Web Access (like TFS 2008) requires the IIS6 management compatibility to be installed when you are using IIS7.  If it is not installed, TSWA will not install.

As I learn more, I'll update this post.  Please let me know if you hit anything.

Brian