Spec Ops Survival, which also contains co-op missions, will also include a ranking system which will track your progress in both co-op and multiplayer modes.
As you rank up, Mission modes will be unlocked and providing how well you do, you will unlock more maps, weapons, and progress in both modes counts towards your overall Spec Ops rank ans tracked by Elite.
You can play co-op online or through split-screen co-op.
Check out a Spec Ops Survival trailer below. MW3 is out in November.