Ok, before I begin, let me tell you that this is illegal, blablabla things we've all heard before.
So basically the concept is this:
Gamestop lets you pre-order games for like $5, but what most people don't know is that you can also pay for the full game when you pre-order it, so that on the day it comes out, you can walk in, and get it for free.
The idea is that you pre-order it, and give them your phone number.
This will let them track you. However, when you pick it up, they don's ask for proof of purchase, they just ask for a phone # and then a signature. On the day it comes out, get your friend to walk in the store, and tell them your phone #, then pick it up and leave. You walk in several hours later, tell them your phone #, and they will tell you it has already been given to someone. Throw a shit-fit that they gave it to the wrong person, and even show them your ID to prove you are the one that should get the game. Well, Game stop employees don't have the time or the follow through to deal with this situation, so they will just give you the box and you will be on your way. In the end, you should end up with 2 WoW WoTLK CD keys.
The problem with this scam is that it is illegal and considered stealing. If the employees aren't lazy, they will probably try to look through the security tapes after they are done working. (They don't have the time to do this during their shift, seeing as how the MAX I've ever seen in the store was 2 at a time, and considering it's the day the game came out, the lines will be fairly long.)
Nevertheless, they might look through the security tapes, so your friend might want to wear a plain hoodie / hat, something not easily identifiable. Also, make sure he looks at the ground a lot, so the visor part of the cap covers his face from the camera. Now that I think of it, Stunner shades would be perfect for this. Make sure you do this at a gamestop you don't go to, such as one in the neighboring city, so no-one recognizes either of you.
If this works, you should have 2 Games / CD keys.
Sorry I posted this after wow already came out, but I only though of this when I was at the register and they didn't ask for Proof of Purchase.
Hopefully, you'll be able to use this tactic with other games that are coming out soon.
Good luck