No, but there are two issues that might make you think so:
Firstly, there's also a beta going on for "Windows Server 2003 sp1", which
has an X64 version. The beta programme also includes "XP Professional
2003 64-bit edition sp1" (for Itanium) and "XP Pro 2003 for x64 sp1", which
is the version for AMD64 (and IA-32e).
Second, 32-bit Windows XP with sp2 will take advantage of AMD64
hardware in one important way: it uses the "NX" bit in the PAE tables,
to implemten "Data Execution Protection" - attempts to run code out of
data memory are trapped. This is intended to prevent buffer overflow
attacks across the network; it should certainly prevent simple-minded
ones getting control of the machine, although they can still do denial-of-
service attacks.
John