Vista SP2 and Windows Server 2008 SP2 release candiates

Microsoft has created "release candidate" builds which should be close to the final version for these important service packs.  

Vista SP2 and Windows Server 2008 SP2 release candiates
http://windowsteamblog.com/blogs/windowsvista/archive/2009/02/25/announcing-the-service-pack-2-for-windows-vista-and-windows-server-2008-rc.aspx
http://www.eweek.com/c/a/Windows/Microsoft-Ships-Service-Pack-2-for-Windows-Vista-and-Windows-Server-2008-RC

QUOTE: This week we are announcing that Service Pack 2 for Windows Vista and Windows Server 2008 has hit an important milestone in development: Release Candidate (RC).  Starting today, the RC of SP2 for Windows Vista and Windows Server 2008 will be available to TechNet and MSDN subscribers to test prior to final release. In the very near future, we will be making the RC broadly available for anyone to download and test. You can expect another blog post from me when that happens.

Summary of Key Changes
http://windowsteamblog.com/blogs/windowsvista/pages/notable-changes-in-sp2-rc-for-windows-vista-and-windows-server-2008.aspx