My MMO experience is pretty light (SWG and SWTOR only). But I really want to heap praise on Zenimax for doing something that seems, to me at least, innovative and extremely gratifying. That is, allowing us to team up without joining a group.
Two (or more) players come up to the same objective at the same time. In any other MMO I've played, if those players aren't grouped, only one player is going to get the objective and the loot. Not so with this game. Obviously, I can't just stand around and let someone else play the game for me, but if players contribute, they get the rewards. You can heal total strangers you'll never see again; you can add dps to a fight; everyone who contributes gets rewarded.
There's still poaching in this game, mostly of items being guarded by enemies--runes seem to be the worst example. But poaching is way down from any other game I've played--because it's not poaching anymore. It's helping.
I really can't praise this mechanic enough. I am thrilled.