I've been meaning to write about this since I first completed Mass Effect 2 early this year, but with the new Assassin's Creed: Brotherhood video demo (which basically showcases the idea, though probably a bit less ambitious) out I'll cut my own ambition about a larger article short and settle for this blog post.
CENTRAL ARGUMENT: Mass Effect 3 need to have a team away-mission management component.
No more hang arounds
I found it quite ridiculous that while you and two members were out fighting the good fight, the rest of the team, which is quite large, just sat around isolated to their own chambers.
Being able to send members, the ones you're not personally taking on a mission, on side missions would resolve many issues and open up a whole new dynamic to the game. This is how you could weave in more of the choices you did earlier into the game. Instead of just emails, missions!
Here's how I picture it working. From your ship (base) you have a team management terminal. Here you can see the status of your whole party; their stats, weapons, skills and fighting status. You'll also have a mission list. These missions would be the sort of side missions you had in ME1 where you were driving around the MAKO. Shorter missions, in and out. You should get a set of missions which expand and contract dynamically as you play through the game. You should have a pick, but also the option to skip.
A mission briefing will explain the setting and purpose of the mission. This includes intel, like enemies and dangers, and rewards (money, equipment, resources). A risk analysis might be provided, but the player must also think about this. It's up to the player to compose a mission team of one to three companions, selected such that the mission success probability is maximised. The right team for the right job.
The core mechanic is this: Sending people on these missions could level them up, provide income, items and even create allies or enemies. The trade-off is that missions will take time, so whoever you send will not be available to you for missions you take on. I think time here would be counted in some measure of main mission time, so maybe assign mission time units to the regular missions, and have the side missions take up a number of those (example: a side mission may complete after you play one long mission or after two shorter ones. In essence player missions are driving the side mission clock).
I would initially not consider it possible for you to actually go yourself on these missions. This for the obvious development resource reasons, but on the surface, because it's time for your team to shine.
Risk vs Reward
The most important thing here is in the dynamics of reward versus risk. Let's talk risks.
There'll certainly be the possibility of missions failing to some degree or another, which could impact you because now you have team members who are injured and will need time to recouperate (invest in the medic bay!). I do not however believe it would be in the best interest of gameplay to make it possible for team members to die on these missions. Not unless the game is very explicit and basically telling you that, for this particular mission, sending this group makes it all but a suicide mission.
You could feed mission outcome back into team morale. Now you'll have to consider if the side mission is worth a possible hit to your 'rep' with a certain character. Certain members might oppose some missions, even though they'd be the best ones to do them. Do you push or give in? On the other hand, we could have bonding between team members because they had mission successes together.
With side missions, why would you need mining? The way I see it, mining is the cop-out placeholder for a proper resource management system, and here is one that I can't see failing.
On a more meta-level I like this idea because the uncertainy of the side mission outcome overlaps your regular missions. This means that if a side mission fails you'll have to really consider if it's worth to reload, because you haven't been sitting around waiting for the outcome, you've been out accomplishing things yourself.
The Final Piece
I readily admit I'm in love with this idea. I see if in my mind, and it fits so perfectly. This sort of mechanism opens so many doors, and it's just the thing ME3 need to be the kind of leap from ME2 that ME2 is from ME1.
I really hope it's a central piece of ME3 already. It's likely too late to add it now if it isn't!