Just in case you got a reservation number from Apple last night and you got the delayed order confirmation from AT&T (10/22 deliveries - I should have known better than to go forward with the AT&T order - they always delay me):
Apple couldn't close the 10/1 delivery reservation because AT&T already showed my back order used up my upgrade eligibility. Call AT&T (877-782-8870) and be VERY FIRM insisting you want to cancel the back order (refuse to accept their "in process" BS - tell them the site and email shows it is back ordered). They can and will cancel, which resets your eligibility status, and lets you go back and complete the Apple reservation order - at least moved my estimated delivery up nearly a month.