Microsoft yesterday moved a little closer to a final version of Windows XP Service Pack 3 after it quietly released Release Candidate 2, the same test version that was released to a smaller group of testers on February 8, for public downloading.

Considering Microsoft is expected to make Vista SP1 broadly available sometime in March and pull Windows XP from the reseller and retail availability list on June 30, it’s reasonable to presume that SP3’s release is imminent, perhaps around the time of Vista SP1, or even sooner.

The update focuses mainly on bug fixes and other minor changes to the operating system, but it’ll also bring a few new features and components, including improvements in black-hole router detection, security credential changes that allow for “forward compatibility” with Windows Vista and Windows Server 2008, Network Access Protection (NAP) support, and a less strict product activation and anti-counterfeit system.