this post is being kept mainly as a referance. I've have started work on the mod, so I hereby declare it WIP! *cuts ribbon*)
Heh, you people must be getting hundreds of these

And, much as I am loathe to burden you with another mod idea topic, I feel this one might have Potentialtm
I don't know if any of you have read the Mortal Engines series (Can't link to wiki article, due to forum rules, but type in Mortal Engines into the search and you'll be there) by Philip Reeve, but the Premise is this. After a Cataclysimic war (the Sixty Minutes war) the world was in too dangerous a state for settlements to be kept stationary. Therefore, Cities and towns were converted into massive 'traction-citys' that moved on treads and wheels. Eventually, due to a shortage of resources, Cities and towns started 'praying' on each other, in a practice known as Municipal Darwinism. Air Ships are a common way of travel other than cities, and have become a sort of merchant fleet, with a giant flying city known as Air-haven, as a trade hub.
Having dealt with back story, my idea for the mod is this
Commander unit is a Traction City.
It produces all units, is quite strong, but rather slow.
Ground:
Infantry Cheap, but very fragile.
Heavy infantry: again, cheap, fragile, but able to do decent damage to vehicles
Buggies: Fast, lightly armed, scout units.
Heavy Buggies: ffectivly tanks, expensive, but powerful.
Troop Buggies: Transports
Air:
Fighter Airship: an airship designed to take down other airships.
Bomber Airships: Airships designed to drop bombs
Transport Airship: Air Transport.
thats all the units I can think of now.
However, I would have to ask that someone else attempt to make it. I really would love to attempt this, but I wouldn't know were to start, and ultimately, i'm not sure i can do the books justice.
Ok while this may be rather brief in terms of brainstorming, this is phase one of my idea. Phase 2 should include Factions, sea units, and possibly 'End-Game weapons'