"In anticipation of a full-blown launch this summer, Microsoft has released trial software to the public for its Windows XP 64-Bit Edition for 64-Bit Extended Systems," reports InternetNews.com.
"The software, which can either be ordered via CD or downloaded (approximately 450 megabytes), is only compatible with AMD Athlon 64 powered desktops or Opteron processor-powered workstations. The trial version will not work on 64-bit Intel Itanium-based systems, the company said."
Comment: The AMD download is here. The 64-bit Itanium version has been out for about a year, and you can buy it running on an HP workstation.