Enough of the "I think" and "I suppose" crap. first off there is already win2k-64 available.
Yes thats a 64bit windows 2000.
Yes, there is already 64bits CPU's on desktops, Alpha
Linux 64 is available but requires a few patches to get operational.
There are a few other 64bit OS's out there, HP-UX, AIX, Solaris, Irix,...
You can try to run the "desiel fuel" applications of today in the rocket engine of tomorrow. Good Luck.
Still unconfirmed, is the AMD designed 64 bit chip. to my understanding this is going to be 2x 32 bit cores on a single chip (double pumping comes to mind), that being said its not a true 64 bit core. SMP on a chip is not a new idea and a SMP machine that has 8 processors does not equil a 512 bit machine. but this is still unconfirmed. When it is Ill be here running it in AMD's face
AMD does have a 64bit data path to cache meory, Intel uses 128 bit data path. AMD would get noticible performance increase in fixing that bottleneck. As we all know Intel smokes the AMD in bandwidth on the BUS.
http://www.spec.org/osg/cpu2000/results/cpu2000.html
NOTICE, the IA64 processors dominating all the SMP x86 and other SMP 32bit RISC CPU's.
AMD will be with the rest of the x86 32bit SMP scores =) if its true about the dual 32bit core.