Microsoft has already announced that they will stop supporting Windows XP within the next 3 years, and now Vista is in it’s crosshairs. Microsoft has made it known that it will stop supporting Windows Vista SP1.
If users want to keep getting support, they will have to upgrade to Windows Vista SP2, though Microsoft suggests it would be better for you to upgrade to Windows 7. Better for them too of course. The company is trying to get everything in order for the arrival of Windows 8 in 2012.