On April 13, 2010 the Microsoft lifecycle team is announcing a change to the Service Pack Support policy and have blogged about it, here: http://blogs.technet.com/lifecycle/archive/2010/04/13/end-of-support-for-windows-vista-rtm-and-recent-service-pack-support-policy-updates.aspx

And official: http://support.microsoft.com/gp/newsplifecycle

I wish you a nice day, tosc