I feel like Call of Duty should have some multiplayer-based achievements/trophies, like Halo or Battlefield. Its always nice to have more gamerscore/trophies on your profile, and it just seems like there should be some, anyway.
Prestige (maybe like 5G or 10G per prestige or 20G the first time and 50G or 75G the last time)
Getting a gold gun
Finishing all of the challenges for a given killstreak
Doing a difficult task a certain number of times in one match (i.e. 10 sniper headshots in one game)
Large multikill with a given killstreak (i.e. 6-in-one predator missile; kill entire enemy team with an airstrike)
I know that they can add achievments (like was often done with the release of DLC), and i think it would be cool to see stuff like this
These are just my ideas. What do you think?