I myself ordered an iPhone 6 Plus 64 GB Silver from AT&T at 1:31AM 09/12/14. It is still pending shipment/preparing to ship and the dates are 10/13-10/22. Nonetheless I am being positive I will receive my preorder this Friday 09/19. I did receive an email from AT&T this morning 09/17 at 4:46 AM that due to the high demand, my iPhone is not yet available to ship. Gotta say some prayers and things will get rolling! Oh, and AT&T withdrew the funds for the iPhone on monday the 15th and its already been posted to my bank account. I did the AT&T Next 18.
I've also been trying the methods posted to track my phone either through UPS or FedEx and no luck.