There is an extremely interesting short statement by Michael Howard regarding MS07-004: The coding bug is in Vista but it does not have any effect: Read yourself: http://blogs.msdn.com/michael_howard/archive/2007/01/10/why-windows-vista-is-unaffected-by-the-vml-bug.aspx
Is Vista the most secure Operating System ever?
This update addresses the vulnerability discussed in Microsoft Security Bulletin MS07-004. To find out if other security updates are available for you, see the Overview section of this page.
RC is though.