Speaking of Resistance 2! I am currently REALLY enjoying the Resistance 2 Beta and I have to say the 8 player co-op is fan-fucking-tastic!
They have structured everything around goals to achieve a mission such as:
1 – Stop incoming forces
2 – Turn off teleporters
3 – deactivate power source
4 – eliminate stalker to move on
5 – Activate Beacon
6 – Secure landing zone
These are just examples, but as you play you really need to work as a team. The soldier class can raise a shield that people can huddle behind as they fire, the medic can heal groups, but both need ammo from the spec-ops in order to use these specials. If you are not tanking and providing cover and the other is not providing ammo and headshots and the medic is not healing you WILL fail.
This is a mode that demands a proper headset (and there are issues with this I will discuss tomorrow) to play properly and I am thoroughly impressed at how they have made teamwork essential.