One more clarification is that since as I said this has been available for pre-order on their site for about 2 weeks now (it showed up on pricewatch.com), you can bet that even if you ordered today, there are lots and lots of people are ahead of anyone that orders now, so even if they do get a shipment in by 8/16, it may all be allocated already, so you're not guaranteed to get it even then.
The bottom line of all this is that there seems to be shortage right now, because demand is very high and supply for some reason seems to be very slow. Hopefully, this will pass, and you'll be able to walk into any store and buy it off the shelf, but who knows how long it would take for the shortage to be over (it could be a couple of months). Just take that into account if you're trying to save a few bucks and play the backorder waiting game. But if you're willing to pay a little more, you could jump to the head of the line. So finally it's your decision - save $50 and wait a couple of months, or pay a little more and get it now.