Service Packs RC availabe to download

Microsoft published Release Candidate for XP SP3 and Vista SP1 .Currently it is avaialable only for Microsoft Technet Subscribers.

Windows XP SP3 RC is a rollup that includes all previously released updates for Windows XP, including security updates, out-of-band releases, and hotfixes. It contains a small number of new updates, but should not significantly change the Windows XP experience

Windows Vista Service Pack 1 Release Candidate (RC),In addition to previously released updates, SP1 contains changes focused on addressing specific reliability and performance issues, supporting new types of hardware, and adding support for several new technologies. SP1 also addresses some management, deployment, and support challenges.

The final versions are only availabe after getting the test reports / feedbacks from the technet subscribers and testers....So we need to wait some more months to get the final versions of these service packs