Hello. I don't know if many people will read this, but I have posted about it on Reddit and on the official Gearbox forums. If you ordered this version of Borderlands 2 (Vault Hunter Edition for PC), you should get your order by release date. The page now shows out of stock, but I have been in touch with Amazon who said:
"Rest assured that your order will be fulfilled on the released date: September 21, 2012."
I got an e-mail last night at about half 12 notifiying me that it was back, ready for pre-order again. But that doesn't seem to be the same here, as it's stll saying, 'Sign up to be notified when this item becomes available.
Last I heard from gearbox is that the vault hunter edition wasn't being made available on PC and was console only, I asked amazon about it but the response I got back from them was somewhat less then helpful, they didn't seem to know if the product actually existed or not. it was at that point I pulled my preorder and just pre-purchased via steam. at least I know I'll actually get it from there.