The plans for rolling SP2 out through automatic update seem to have changed to allow corporate customers using XP Professional longer to use the SP2 Blocking tool, which allows them to prevent SP2 being downloaded for 120 days. As it stands currently the plan seems to be
8/16 Release to Software Update Services
8/18 Release to Automatic Update for users running Windows XP Home Edition only
It has been rumoured that from the 25th the following should be happening, however Microsoft have not said anything other than ‘later in August’.
Available via Automatic Update for users running Windows XP, All Variants
Release to Windows Update site for interactive user installations
If you don’t want to wait for automatic update you can download the Express installer (English) which is what you would be offered via Automatic Update here
For a single machine install this is probably the best thing to get as it is a smaller download tailored to your system (60Mb+ download depending on XP Edition). Remember also to order yourself a SP2 CD-Rom from http://www.microsoft.com/windowsxp/downloads/updates/sp2/cdorder/en_us/default.mspx
The 266 Mb network installer recommended for installing SP2 on multiple machines is available from:
http://www.microsoft.com/downloads/details.aspx?FamilyId=049C9DBE-3B8E-4F30-8245-9E368D3CDB5A&displaylang=en