Peter Oppenheimer noted that Apple has experienced significant constraints on the new iMacs, and was only able to ship them during December. Without these constraints, he says, Mac sales would have been higher....
Cook further addressed this in the
Question and Answer section.
Cook also mentioned a few other minor factors, including the weak PC market and the impressive sales of the iPad. Apple sold more than 23 million iPads, and Cook said that some cannibalization was almost certainly a factor.
Article Link:
Apple Blames Low Mac Sales on iMac Supply Constraints