I did hope this option was available but it wasn't, don't think it would be financially viable for ED to do so... think that was as I had read in a thread sometime ago
It wouldn't be worth it since you'd be paying production cost, and there is little if any difference between the production costs of the rebirth and 1 gig units. As far as I'm aware.
Either way sucks for him since he has already paid the full 1Ghz price. Those waiting for a 1Ghz preorder from Craig have no good options to get fast delivery.