Microsoft made available on December 3 for download the near-final Release Candidate (RC) of Windows XP Service Pack (SP) 3.
The RC is available to all Microsoft Developer Network (MSDN) and
TechNet subscribers. This isn’t yet a generally available, “public” RC
of XP SP3; that is still coming at some future date that Microsoft
hasn’t disclosed.
http://blogs.zdnet.com/microsoft/?p=1004