Best Buy's online order system is not very good. I had to end up calling them and switching it to in store pick up as the order status kept changing and at the end was a 1-2 week shipping time. The agent did not even know what the status meant. But the agent was helpful to switch it over. Hopefully no problems in picking it up.
I just got off the phone with a Best Buy CSR because my order state kept getting reset. He seemed pretty knowledgable. Basically, it amounts to them not having the product (or enough of the product). When he noticed it was a pre-release order, he mentioned that it looks like they have not received all of their release stock.
Based on my own assumptions from the call, it sounds as if that when their internal system recognizes inventory, it flags all pending orders to process. Some orders get fully processed and shipped and the others get reset because there is nothing to ship. They get more units in and the process starts all over again. Don't take that as fact as it is pure speculation on my part. It just seems to align with the CSRs comments and would explain why the order would go through the whole ordering process again.
He also corrected himself when he mentioned "back-ordered". Because they haven't received all of their initial stock it seems, they can't consider the product back-ordered.
It does seem like you may have better luck getting a unit in store (though that is speculative as well as I remember Best Buy only having 3-5 units of each model of various other gadgets in the past on release).