Ahahaha! I saw Gaia: in the thread title, and I'm ecstatic to be recognized for one of my ideas! Thanks for the boost, Player One!
I thought of Gaia as being a third team whose build-ables would be placeable in !layout, or perhaps even GTKRadiant.
Gaia is the mapper's way of having nearly any object in their map that can be destroyed.
Gaia could have a range of build-ables that could be worked into maps.
Here's some ideas I've thought of and that others have presented to me:
-A factory that spawns NPC sentinels to roam the map.
-Barrels and boxes.
-Turrets or defenses that attack one or both teams.
All of these things would be destructible. Whether it be just for eye-candy (boxes or barrels that explode when shot) or something that can alter game-play (a high HP sentinel factory that requires the co-operation of both teams to destroy), it can be implemented as a build-able with the use of a third team, Gaia.
-Now that I think of it, the automated defenses and the sentry factory would go excellently together, no? The old idea of the Sentry Factory could easily become real, now. We have the AI, we have the ideas, now all we need is a third team, some models, and a shit-load of testing.
-Oh, and the idea of the name Gaia came from my days of Age of Empires map editing. The name of the NPC team, which ranged anywhere from destroyable trees, rocks, and fortresses, to NPC sentries that attacked anything that moved. Gaia, meaning land, or earth. Hell, you could go as far as to say "nature". Something that cannot be controlled.
-@Rocinante: Think of it as a.. pre-review. It'll probably happen, we're just ironing out the creases.