Joe, I haven't tried the Beta, but on the MSDN site it is identified as Windows XP 64-Bit Edition For 64-bit Extended Systems (English). I don't know if AMD64 appears in the package after download.
Intel's designation (IA32e) does seem a little out of step.
Old: http://www.investorshub.com/boards/read_msg.asp?message_id=2321056 The Windows Server 2003 family supports two different 64-bit architectures. The first is based on Explicitly Parallel Instruction Computing (EPIC), and supports the Intel Itanium Processor Family. The second is based on 64-bit extensions to the x86 instruction set, and supports the AMD64 platform.
New: http://www.microsoft.com/windowsserver2003/64bit/benefits.mspx The second 64-bit architecture supported by the Windows Server 2003 family is based on 64-bit extensions to the x86 instruction set, and supports both AMD64 and Xeon processors with 64-bit extension technology. This platform lets you take advantage of the wealth of existing 32-bit Windows applications, while also powering the latest 64-bit technology. Find out more about Windows Server 2003 for 64-Bit Extended Systems.