In March of 2008 Microsoft released the Windows Vista SP1. Over a year later you are now treated to the next stand-alone Vista Service Pack. Vista SP2 has been available to MSDN and TechNet subscribers, but now it is available to all.
Service Pack 2 for Windows Server 2008 and Windows Vista (SP2) is an update to Windows Vista and Windows Server 2008 that supports new kinds of hardware and emerging hardware standards, and includes all updates delivered since SP1.
The new Windows Vista SP2 packages are available for download on the Microsoft Download Center site. For details on SP2 read this KB article.
In a couple of months you can finally leave Vista behind you and get Windows 7.