I just found out that Microsoft is now offering this! Cool now I can tell people where they can get help…

From the support page:

Free unlimited installation and compatibility support is available for Windows Vista, but only for Service Pack 1 (SP1). This support for SP1 is valid until March 18, 2009.

Here is the link: http://support.microsoft.com/oas/default.aspx?LN=en-us&prid=11274&gprid=500921&x=15&y=14