Apple is quietly padding the buffer on new, completely stock 27-inch iMac shipments to 3 weeks, for reasons we assume are tied to their well-documented manufacturing issues.
(You've probably heard us talking about the iMac's production problems with yellow and flickering screens, but if not, follow the Faulty iMac Saga here.)
Notably, Apple has not delayed shipments on 21-inch iMacs, even though they, too, can be afflicted. In all fairness, however, I've found reports of 27-inch iMac problems to be far more prevalent.
While Apple hasn't released a statement as to the reasons for delays, we can only hope the company has decided to pin down whatever issues are occurring as opposed to mailing out more broken computers and hoping nobody would notice. [AppleInsider]