After the complete failure that is ordering from Microsoft, I reordered through AT&T. A few hours later, I received an email saying "We have processed your order and it has been sent to our warehouse for shipment. Your order cannot be changed or canceled at this time."
Obviously it isn't shipping yet, but I also noticed that there's no hold on my credit card, so I'm not sure what's actually happening. I had a different shipping address than billing address on my order, so I called AT&T to make sure that it had really gone through and they said everything looks good. I have never had so much trouble preordering something.