What are you talking about, Itanium is not even a x-86 processor , its not available for OEM , its called apic technology , they had plans for them to be shipped for Desktops and consumers , but they scraped the idea ,thanks to AMD, i guess the one which was talked about originally , is the EMT64 technology , Extended Memory Addressing , which means 2 to the power 64 is the bytes which they can address virtually , breaking the 4 gb 32 bit limit per processor .
Windows XP 64 bit which origially came out back in nov 2001 was for itanium, now its for x86 technology 64 bit primarily for athlon 64 and opteron in the Beta stage , (2003) and later added support for intel as well .
Itanium 2 has been around for more than 5 yrs , its not new ,its still in use in the super computing arena,But Microsoft scrapped the idea of supporting that anymore .
Does that cover everything ?