Dan, Re: Intel has millions of NX capable Windows/Linux 64 capable chips that they decided not to sell yet.
If what UPC says is true, then DX capable chips are probably in validation stages right now, since they are supposedly shipping in Sept/Oct. As for EM64T, you don't need a separate manufacturing lot for these. They are in the current chips being sold right now, except fuses inside the chip disable the functionality. So those chips are selling right now, except in workstations (Nocona), they are selling for a little more.