i quote
DO NOT CLICK DOWNLOAD IF YOU ARE UPDATING JUST ONE COMPUTER: A smaller, more appropriate download will be available soon on Windows Update. To receive this download, turn on the Automatic Updates feature in Windows XP to receive an optimized download of SP2. Please visit
Protect Your PC for more information on receiving Windows XP SP2
That is on the page it is for IT Devlopers and proffesionals IE: wait till final release to public on windows update page
