I ordered 2 up-to-date copies for work and as of this moment, they are still Open. But I expected that, because I didn't order until Wednesday the 22nd. No biggie because the wife's on her way to FedEx, as I type this, to pick up our personal copies that didn't get delivered yesterday. All I gotta say is they'd better give 'em to her...
For those who think they are being screwed over, it's unfair, etc. My guess is that it's not quite as random as it seems. Apple ships from many distribution centers around the US and around the world. In most cases, your copy will come from the center closest to you. If for any reason that center has problems or runs out of stock early, then probably people in that region will be affected. So it probably doesn't only have to do with the time of order, but also other factors such as this.
Besides, in the grand scheme of things, who cares? It's not like they signed a contract with you to guarantee delivery, and it's not the end of the world. It's a great OS upgrade, but just an OS. No sense in getting all worked up over a few days. Now, if your order slips through the cracks and takes 3 weeks while your next door neighbor gets the exact same thing in 2 days after you ordered, then you can get all mad.