Seems Like MS will have its 64Bit Version of Windows XP in enough time, when Athlon-64 is launched in September. That is, IF the A64 actually comes out then. It has been delayed for over a year; so I'm not holding my breath.
BUT for A64 to succeed, it NEEDS SOFTWARE that you and I can go out an buy that is optimized for 64 Bit operations. Without that, I think that this chip will struggle for a while. And AMD really needs to ditch this XP Pr ratting system, its antiquated, and has recently been proven to be not a reliable indicator of chip performance compared to a P4.
But it all boils down to available software at the Athlon 64's launch. I'm sure hat most people will consider the A64 only if they can find titles they need, and the software is optimized for the A64. I mean, would you pay a premium for the Athlon 64 & a new Motherboard if you really didn't see any performance benefits over a P4 3.2 Ghz with HT and a 800Mhz FSB. I wouldn't.
That's my $0.02
And I really hope this doesn't devolve into a flame war!