hi, quoted from microsoft vista official website http://www.microsoft.com/windows/windows-vista/default.aspx
"Support for Windows Vista without any service packs will end April 13th, 2010. After that, you will no longer be able to get security updates."
i would interpret as, any computer which has vista without any service pack installed will not get any security updates after april 13th 2010, but the one with any SP installed will still be supported. therefore, simply install service pack 1 and 2 will prolong the support life time.
