if i go to my local gamestop at midnight without a preorder, do you guys think i'll still be able to buy a copy?
Yes but they will make you wait until everybody who arrived with pre-orders gets their game first.
Usually it goes like this: 10:00pm-11:58pm Gamestop gives out numbers to people who have pre-orders. Get there earlier and you'll get a lower number. At midnight they will make everyone line up numerically, number 1 being first of course. (If there is a lot of people they will make you line up outside the store and let only a couple people in at a time.) When it's your turn you give the cashier your numbered receipt and money if you didn't pay it off yet, then they will give you your game and ask if you want to buy the guide.
If you go up to that cashier without a number they will make you wait to let someone with a number get their game, even if you have a pre order. (you'r fault for not coming earlier)
If you don't have a pre-order you're better off just going to walmart and buying it there, it will probably be quicker.