I pre-ordered my 4 from Apple online on midnight (morning) of pre-order day. Picked up at the Apple Store and renewed on Launch Day.
Ok, i'm sure this is a stretch, but if At&t keeps saying that it is apple setting the date & rewarding early adopters, - where did anyone that is getting the discount on Oct 7 order your iphone 4 from originally, Apple or At&t?
I ordered mine from at&t but you could have easily ordered your at&t iphone directly from apple as well - wonder if the people already in the Apple system are the ones that got the earlier date?