It looks like the folks in Redmond have a busy time, after Internet Explorer 8, Microsoft now announces that the Windows Vista Service Pack 2 has reached RC status. I suggest they keep up the speed and bring us Windows 7 soon as well.
More information is available here:
Announcing the Service Pack 2 for Windows Vista and Windows Server 2008 RC
Notable Changes in SP2 RC for Windows Vista and Windows Server 2008
Hotfixes and Security Updates in Windows Server 2008 SP2 RC and Windows Vista SP2 RC