A quick warning to any Apple happy fans of Call of Duty, buying the game from the App Store will cost you. As of 1/26 the keys you get from Apple are not flagged for online play and will act as if you pirated the game.
An inauspicious start to Apples first attack against the more mainstream digital game retailers like Direct-2-Drive and Steam. Apples first real foray into selling mainstream titles (albeit 2 year old ones at their original full price) could be their last as they sell titles without even checking that they work properly.