I too pre-ordered from Gamestop. It's a 10 - 15 minute drive for me, but I wanted the pre-order costumes, and the people working this GS are cool.
I still need to pay off the remaining $8.56. I know it's a weird number, but I've just been avoiding paying it off. My pre-order aint going anywhere, and as long as I pay it off a day before launch, I'll still be guarenteed to get the costume pack (which I plan to sell on ebay immediately)
If you're a member of Newegg and have purchased something there before and subscribe to their newsletter(which is just their daily deals. such an annoyance honestly,) you'll get the code before the game comes out more than likely. The codes can also be used unlimited times on preorders $49.99 and up, just one per order.