Right, there have been a few screenshots from the Agents of change DLC released, and I thought I'd go over some of the less obvious points you may all have missed.
So without further ado, screenshot the first!

http://www.splashdamage.com/screens_brink/dlc01.jpg
This is clearly the labs level, deep within the bowels of the Ark. In a spectacularly-detailed left hand we can see the fire-spreading Napalm grenade (Soldier-specific). It also appears there will be a door the Resistance need to blow up in order to progress, and this indoor level will be pretty vertical (at least three floors).

http://www.splashdamage.com/screens_brink/dlc02.jpg
Another screenshot showing the same match. Something about a Sequencer in the Objective, probably a Hack. Not sure what it says before it, though. There's at least one Supply Command Post of this map.

http://www.splashdamage.com/screens_brink/dlc03.jpg
Here we have a room which looks fairly high security in the canon "ACCESS DENIED" on the right hand side. The player is an Engineer, and it looks like he has the new "Pyro Mines" unlocked (the "Y" shaped symbol in his equipment bar). You can see a window in the top-right, further suggesting some sneaky Z-level based sniping on this map. Also of note is the Resistance' Shield, attached at the front here. Looks like it'll only be much good when ADSing, but we'll see. I imagine it'll cripple your stability/accuracy somewhat, but may reduce recoil. Pure speculation on my part. Equip speed will probably take a nosedive too. Pretty nice detail is the tally of kills on the inside of the makeshift shield.
Also, right behind your ally, it says "ARKAQUA". Maybe this is where the Founders have been "treating" the water? Conspiracy nuts, go wild.

http://www.splashdamage.com/screens_brink/dlc04.jpg
This is an interesting one. Seems like a storage room, what with all the barrels. Is that a "branch" type symbol on them (check the top left)? Who knows. Playing as the Security Medic this time, with a much shinier shield.
As the link suggests, I think this is in the lower sections of the Tower map. Reasons being, it look like this is a "No Access" area due to all the tape in the background of the image (through the doorway), and the scaffolding around the place lacking the Ark's typical clean decor.
The other, more obvious reason, is the clouds visible through the scaffolding. Perhaps this is post-missile hit? Or just a lower down area of the tower, not in view of the rest of the world. Alternatively, it is still the Labs, they aren't as deep in the facility as previously thought. This seems more likely, unfortunately. They must be keeping the tower under wraps for now, along with the new costumes.
You can see both in the Equipment bar AND in the centre-left side of the screenshot, the new Healing Beacon! With a snazzy AOE effect of healing anyone nearby. No indication of whether it works on friend-or-foe alike, but I imagine it has the same base mechanics as the Lazarus 'nade in terms of who it heals. Here's hoping the Resistance one looks more mis-matched, or maybe stolen? It'll be much more vibrant, I imagine.

So there we go! Hope I didn't miss anything, if I did, feel free to leave your own opinions/ideas.

Let the hype commence!

Just wanted to add that in picture 4, all of those barrels have wires coming out of them.

Guy in the shot of the final screen shot appears to be wearing some sort of new goggle-like clothing item?

Is it possible that in the Labs mission, the Security is investigating the vaccine and the Resistance is trying to retrieve it?

Here is something I noticed that really stood out to me about the DLC:

The screenshots are showcasing a new HUD style. Obituaries have moved from the middle-right side of the screen to directly above the radar, and the D-pad Objective Wheel and active Abilities are now in a rectangular formation, with the Supply Pip Meter immediately above that.

Now, I see that the Objective Wheel/Abilities are hotkeyed to "MB3", and "3", "4", and "5": assuming that "MB" stands for "Mouse Button", then this HUD arrangement is specifically for PC.

PC gamers, has this always been the case for you? I can see how this would be an improvement for you folks over the console's circular D-Pad arrangement, so I have no issue with that for you.

But as an Xbox gamer, I personally like the original arrangement and I hope that doesn't change for the console. Does anybody know if that is the case or not? Sources are appreciated, but I am aware that the Brink team has been unusually tight-lipped recently so I'm not going to scream "LINKS OR IT DIDN'T HAPPEN" if you don't provide any.

Thanks.

I just posted this question in the Gameplay subforum, but while there was a discussion about them here too I thought I would share my question/thoughts.

thats just how the obj. wheel looks on PC there not gonna change it for consoles.

good eye!! i bet resistance is gonna blow the roof like nakatomi plaza in die hard.