It seems to me (correct me if I am wrong) that Apple has simply removed the Processor Module from the 1.6Ghz G5s and replaced that with a dual 1.8 Module and added another heat sink. There is no difference whatsoever to the other specs... This tells me that one day it will be very easy for Sonnet Technologies or PowerLogix to bring out Processor Modules. Which is always great news. My 1.8Ghz G5 may one day become a dual 3ghz for only $499.