"Pre-order Tom Clancy's Rainbow Six Vegas 2 and receive the code to unlock the Comcast Optimized MLG map! Optimized for more intense multiplayer face-off, this GameStop exclusive is only available through pre-order. Offer is good while supplies last. Codes and instructions for how to unlock the map will be included in the game's box. See stores for details."
-Straight from gamestop vegas 2 page.