Now available beta/trial version for download or via CD.

http://www.microsoft.com/windowsxp/6...n/upgrade.mspx
System Requirements:
•Supported processors: AMD Athlon 64, AMD Opteron, Intel Xeon including Intel EM64T, Intel Pentium 4 including Intel EM64T
•256MB RAM
•1.5GB available hard-disk space
•Super VGA (800x600) or higher resolution video card
•CD-ROM or DVD drive
•Keyboard and Microsoft Mouse or compatible pointing device

Important: Windows XP Professional x64 Edition cannot be successfully installed on 64-bit Intel Itanium–based systems.
Go get your copy......