Tomorrow (25th of August) according to Microsoft announcements, will be the day for the Automatic Update release of Windows XP Service Pack 2.
I hope so, but I think that the Automatic Update requests will be a great amount, so there could be problems with the Windows Update service.
However, after the XP SP2 installation, I think we've to bookmark the link to the Microsoft Knowledge Base Article - 875355: How to use the Automatic Recovery feature to recover your computer if the Windows XP Service Pack 2 Setup program is not completed successfully.
This article discusses how to use the Automatic Recovery feature to recover your computer to its previous configuration if the installation of Microsoft Windows XP Service Pack 2 (SP2) is not completed successfully. Use the procedure that is discussed in this article to recover your computer to a bootable state and to remove Windows XP SP2 if Windows does not start correctly after you try to upgrade your computer from Windows XP to Windows XP SP2. This article also discusses how to collect information about the Windows XP SP2 installation and about your computer to help troubleshoot and diagnose the issue.
Bookmark it... could be useful!