I dunno for sure, but I would venture a guess they will process payments (they haven't as of this writing, for me) when the open up shop. I would assume all the codes would be emailed/applied at one time (after all payments have been made). Just guessing though.
I was just billed, and my order shows as "fulfilled" and it "closed," but I wasn't provided with a retail key. Instead it shows my head start serial number. I'm hoping I'll receive an e-mail with the actual retail key shortly.