2/28/11 (Title Update 7)

Issues Addressed:
Matchmaking improvements to return higher quality results faster. This change includes settings that are tunable in the live environment, so tweaking may continue beyond initial release of this update.
The in-game store now hides DLC map packs that do not match the language of the players disc to decrease the possibility of users downloading the incorrect language version.
Calling in a Chopper Gunner immediately after getting shot down in a Gunship will no longer end the Chopper Gunner run prematurely. Required timing-specific button presses.
Split screen players are now able to change camera perspectives and cycle through players as a spectator.
Addressed an issue where the most recent match played in Zombies could overwrite the best match played on the leaderboard.
Improved Zombies lobbies to prevent players from erroneously receiving the error Unable to join game session under certain circumstances.
Addressed a number of community-discovered Zombies gameplay exploits.
Additional security feature updates.

Gameplay Tuning:
Additional sniper rifle tuning.


From callofduty.com