News flash! Windows XP SP3 is due in the first half of 2008. Windows Server 2003 SP2 rolled out in mid-March. If you'd like to 'get smart' about service pack availability, the Windows Service Pack Road Map at http://www.microsoft.com/windows/lifecycle/servicepacks.mspx deserves to be on your short list of favorite web pages.
It lists all of the NT-flavored Windows operating systems, provides links to the latest (and immediately previous) service packs, and provides projected dates for the next service pack.
Whether you're building a Windows XP slipstream edition (see the July 2007 issue of Maximum PC for details), creating a library of service packs you can distribute to users, or just wondering when the next service pack will arrive, this site's for you. Being able to download a service pack and burn it to CD or DVD for installation sure beats messing around with Windows Update, especially if you're stuck with a flaky online connection or are worrying about bumping up against so-called fair access policy download limits on satellite Internet services.