Is there a download for this somewhere that I can't find. Installing ASP.NET MVC itself doesn't seem to add any documentation to the help browser in VS2008. It exists in the online MSDN library though:-

http://msdn.microsoft.com/en-us/library/system.web.mvc.aspx

 

I re-downloaded and did a repair with the MSI of the VS2008 SP1 documentation set just to check, and that doesn't include it.