I tried the myATT app at midnight and it didn't work at all. It kept erroring out and pushing me further down the queue. So instead i went through the Apple Store app and was one of the first ones to get in so I got to place an order for a 64GB Silver (i refuse to pay more than a grand for a phone), but the order wasn't complete because they couldn't contact the ATT servers to verify my upgrade eligibility and they didn't have the 30 month Next option. I wake up this morning (well 5AM pacific) and on a whim checked the myATT app again to see how far the dates had slipped. Only they hadn't... I just ordered my 64GB silver through ATT for delivery on the 3rd. I'm thoroughly impressed.
Identical scenario on my end but I went with the 256GB.