Not only does AMD have the only desktop 64-bit offering right now, but their chips are much faster than Intel's at the same clockspeed, even in 32-bit mode. Whereas Intel's engineers are just running their chips at insane clockspeeds, AMD's are actually designing better processors. For the price of a 3.4GHz "800"MHz FSB P4EE ($989 on pricewatch
right now), you could buy two Opteron 246s ($441 each) with cash to spare. If you want to talk raw, meaningless numbers, the Opterons still beat the P4EE (4GHz and 2MB cache total). Of course, SMP isn't simply additive like that, but consider the advantages of 64-bit and multiprocessing, and the fact that AMD chips are
/much/ faster than Intel's at the same clockspeed (even on 32-bit code), and there's no contest. All halfway-modern Windows versions and Linux kernels can support SMP, and the latest support amd64, too.