Now that Windows Vista Service Pack 1 has enjoyed a few weeks in the limelight in which to entice the "wait-for-SP1" IT shops to jump to Microsoft's latest and greatest client operating system, it's time to introduce the OS upgrade we've all been waiting for: Ladies and gentlemen, put your hands together for Windows XP SP3.

Today we are happy to announce that Windows XP Service Pack 3 (SP3) has released to manufacturing (RTM). Windows XP SP3 bits are now working their way through our manufacturing channels to be available to OEM and Enterprise customers.

We are also in the final stages of preparing for release to the web (i.e. you!) on April 29th, via Windows Update and the Microsoft Download Center. Online documentation for Windows XP SP3, such as Microsoft Knowledge Base articles and the Microsoft TechNet Windows XP TechCenter, will be updated then. For customers who use Windows XP at home, Windows XP SP3 Automatic Update distribution for users at home will begin in early summer.

Microsoft released the third service pack for its now-venerable XP operating system to manufacturers this morning, which is good news for the many organizations who've yet to find a reason to undertake a migration to Vista.

XP SP3 is a rather modest upgrade, one that falls much more in line with XP's first service pack than with the security feature-packed SP2 release, but the new service pack stands as an important reminder that while XP will soon leave the retail channel, the operating system on which most organizations have come to depend is still very much supported by its maker.

The biggest new feature in XP SP3 is the addition of support for Windows Server 2008's Network Access Protection, which is aimed at enforcing network health by determining policy compliance on systems that access your network. Whether XP SP3 will be interpreted by Windows sites as a green light for NAP deployments remains to be seen, but it's clear that NAP would be dead on arrival without support for Microsoft's biggest platform.

In my initial tests of XP SP3, in an update-from-SP2 scenario (clean-install-from-slipstreamed-media tests are on the way), I haven't run into any problems, nor have I experienced any performance increases or slowdowns.

I can report, however, that my favorite feature from Windows Vista has made its way back to XP. As with Vista, XP may now be installed without providing an activation key during the installation process--a major boon for testers who need to spin up XP installations for brief periods of time before blowing them away.