My first post here but I've just called the Exeter store and they know nothing else. He said he is checking the Apple site just the same as we all are and the latest info will appear there. He also said that I was about the 20th person to call this morning....
Apple on line advisor has confirmed release of 21.5 iMac tomorrow but unable to confirm if it will be available in store... Quote " We have no specifics on a time or release "...!!!