I did similar, or even better - Fortunatly my local store's GM has made herself available for questions from customers like me, so I contacted her!
My areas store will indeed have the internet in-store pickup orders available at midnight and on reserve at the CS desk.
So definatly check your stores everyone if you have a in-store pre-order that you want to pickup at midnight!
See you all in Azeroth real soon..... just be careful of that huge dragon going around.
Do not shop Best Buy.... They do not back the product they sell and their employees are rude!!!!!!!