So here is my experience in case it helps:
After placing the order with my AT&T billing address, I called in try to change the shipping to my desired address. I used the method from above about calling macbook sales and asking to be transferred, and spoke to someone within 15 minutes. I was told it was no problem to change the address. He changed it and said it would take 24-48 hours to update online and to recieve an email confirmation. The time was 11:30am eastern.
As of 8pm this evening, nothing had changed on my end, and I had received no email. So I decided to call again, and using the above method again I spoke to someone in about 20 minutes to verify the change.
They told me that the request to change the address had been submitted to the "back of the house" but they have been having issues with AT&T orders. Specifically with changing the address. Therefore they didn't know if the change would be made before it was shipped. They then told me that if it does ship before the change, apple will submit a request to the shipper to change the address, and I should still get the phone on time.
I asked about changing the shipping on my end using ups mychoice or fedex delivery manager but he said that this can cause problems because Apple has an agreement with the sippers that they are only to make changes that come straight from Apple.
So here I am, hoping Apple wasn't feeding me b.s. and that my orders arrive on time at the address I need them to be at. Sorry for the long post but I figured I would share it with yall since this forum has been so helpful for me.
Dude, I used this trick but went to the Mac Pro tech support, it worked in like 1 minute. Thanks!