After delaying the availability of Windows XP Service Pack 3 through its Download Center for one week after an incompatibility problem was discovered, Microsoft has now opened it up to automatic distribution.
SP3 actually was released last week, but in a limited fashion: by direct download, specifically through links on Microsoft's Web site, on its FTP site, and on services like BetaNews FileForum, as well as through retail and volume licensing channels. Now, consumers who use the Windows XP client and who have Automatic Updates turned on will be alerted to its availability, though Microsoft informed BetaNews earlier that SP3 should not yet have been made to be installed automatically. In other words, XP users shouldn't wake up one morning and find SP3 on their systems.
The delay, as it turned out, was triggered by an incompatibility discovered between SP3 and Microsoft's Dynamics Retail Management System, which is actually still being worked out. Customers with RMS are still being advised not to install SP3 until the problem is effectively resolved; Microsoft has yet to say exactly what the problem is.
Source: BetaNews