There might be a delay from the dealer however. I ordered mine in August also and am still waiting. The factory has to "pick up" the order before you get an order number. I am hoping that will happen in November sometime.
You get the order number immediately if you have ordered one of their alottment for the first shipment. In my case the dealer had two alotted for the first shipment and I ordered the 3rd. The process for "out of 1st shipment orders" is for them to fax the order in. Then when it is picked up from the factory you get an order number. This of course is screwed up in part because the first shipment was supposed to be around 3,000 cars and it was only 460. I was skeptical of this process until I was able to have it verified through emails with GM.