Sadly, I'm not a member of a team or clan yet but I see huge potential in MW3 for those groups. For those who are in clans/teams/etc, I want to talk tactics.
For example, the strike packages look like an awesome way to do some honest boosting (oxymoron, right?). A five man team with two assault and three support could probably get a chopper gunner every game. And if you're playing Domination, the support guys would be capping flags while the assault guys get kills in defense. It seems so awesome to me, just thinking about it.
Anyway, this sort of class-based approach has huge potential.
So I'm curious: what else could happen? Or better yet, what do you guys do now? I do so much lone-wolf stuff I forget there might be people who actually work together ...