The links have been posted here before, it's been discussed, at length.
Non Xeons aren't dual capable. Xeons are EM64T capable (at least, Xeons that aren't dusty leftovers from prior quarters are). X86 servers that aren't PCs putting on airs use Xeons or Opterons.
Xeon sold about 800K systems last quarter while Opteron sold about 90K systems. There were another 700K X86 servers that had neither Xeon nor Opteron in them - are you suggesting perhaps 350K PIIIs and 350K Athlon MPs?