The problem is, 3rd edition doesn't particularly promote teamwork. About the closest thing you get is buffing. The best buffer in the game is the least favorite class - the Bard. Other than flanking, there isn't a whole lot you can do to work together in 3e. Yes, there are some things, but, not a whole lot of things.
4e seems geared around the idea that it's a great idea to do something AND help your buddy at the same time. In 3e, it was pretty much always a choice - attack or cast a buffing spell; full attack or move and single attack with a flank. Usually either/or situations.
At least, that's what I seem to be taking from things.
That's exactly it. Most of the buffs in the game are either minor actions or part of a standard attack action. It's not like 3.x where you had to either choose being support all the time or just play an uber-cleric who ignores healing.