I've been playing Brink for a little while. I've leveled up 2 characters to 20, reset their points, and experimented with different classes to see how they feel. Unfortunately, Brink is starting to become a little stale for me.
The thing that seems to be missing and making the game a little stale for me (with both AI and human teammates) is that for a game about teamwork there is no real communication, the essence of teamwork. Predefined objectives list ways to help your team and give an illusion of teamwork, but it isn't real communication because you don't really have a say in what other people do.
If you were really in battle, you would be communicating information and tactics to your teammates even if you aren't the leader. You should be able to tell: an Engineer where to place his landmine, someone to buff someone else, which areas to hold for a push, where immediate help is needed, who should do an objective, or someone to switch their class. What I'm talking about is player-created (ex: put your turret here) and player-assigned (ex: you escort the hostage, you capture a command post) objectives. Brink's Squad Commander isn't very helpful when he's yelling at you to capture a command post when you are seconds away from losing your main objective.
How would this work in practice? It'd be a section on the Objective Wheel called the Command Wheel that allows you to access squad commands.
It would be similar to Mass Effect 2's squad command. Your squad's AI in the game wasn't great, but you could least tell them what to do and they'd do it (see http://www.youtube.com/watch?v=9fxe9Q2BQnM#t=1m04s from 1:04 - 2:18). That control over your support proved crucial to the game experience. You could tell a teammate to go to a certain location by looking at it, hitting a button, and they would go there (see http://www.youtube.com/watch?v=o7ZMq-PZFwU#t=1m09s from 1:09 - 1:46), allowing you to coordinate all efforts not just the high-level ones. The same holds true for human teammates. "Go to the left side" doesn't quite work as well as a distance indicator on all your teammates screens that shows exactly where you're talking about.
The fine details of logistics are a separate question. For example, I think a human should be able to order an AI teammate to do something but only suggest a human teammate do something, but that is all up for debate and I won't pretend to know exactly how this would best work.
What do you think of this (admittedly rough) idea? How would you improve it?