According to the following ad for GameStop UK, owners who are, I suppose, disappointed with Battlefield 3 can trade it into GameStop before November 18th to get Call of Duty: Modern Warfare 3 for 99p.
If you purchase Battlefield 3 before October 27th, purchase Call of Duty: Modern Warfare 3, and finally return Battlefield 3 to GameStop in a pre-paid envelope, then GameStop will totally screw up this deal burglars will know which packages to steal GameStop will refund your credit or debit card so that you only pay 99p. Of course, they must receive the game before November 18th, the game must be in full working condition with all the original documentation, and Royal Mail must not have lost your mail… for this offer to apply.
Will we see this offer in U.S.? I'm not even sure I want to see it.