Don't get your hopes up too much. 800Mhz G4s are rare and expensive as it is, without going into 1.3GHz ones. And getting the chips is only the start - they have to be turned into boards, which isn't going to be easy when they're too expensive but all for a few people to afford.
And when they finally do get them, I suppose people will demand 2x 1.8Ghz ones instead...
