There's no official word from Microsoft, but Neowin is reporting a schedule for the release of Windows XP SP3.

The schedule, as reported, is thus:

April 14, 2008: Support is available for the release version of Service Pack 3 for Windows XP

April 21, 2008: Original Equipment Manufacturers, Volume License, Connect, and MSDN and TechNet subscribers

April 29, 2008: Microsoft Update, Windows Update, Download Center

June 10, 2008: Automatic Updates

Previous reports indicate that XP SP3 adds nothing substantial for security or features; it is mostly a vast rollup of previous updates. It would therefore be a good idea not to go install it as soon as it is available, at least not without a full system backup. Microsoft is facilitating this approach by not making the update automatic for almost 2 months after it becomes available. In fact, there are already reports of problems with systems after the installation of release candidates of SP3, such as Media Center systems to which the "banana hack" has been applied not being able to log on to domains.