Hangars (4)
Multiple levels of corridors (2 so far)
Armory (none so far...working on it)
Warthog Lot (4)
Command Deck
Cafeteria (multiple, undecided on number)
Life Pod Decks (mayber...don't know if I want them)
Engine Room (maybe two)
As you can see, this map is going to have a lot it may be quite big but I feel it will be worth it when its done.
So far, I have the four Hangars, hangar exit corridors, warthog parking lots, stairwells and adjoining corridors modeled. Most of the modeling was taken apart from the Campaign, but some (hangars, certain corridors) have been drastically modified or created by me. Here is what I have:
(keep in mind, i haven't skinned yet and the ship does not have a hull. The hull will be designed once the ship is complete.)
My overall progress so far:
The four hangars and branching corridors. If you can see the little green dot in the very center, that is where the rest of the ship will start to branch off (there will be more corridors branching from the stairwells as well).

Corridor/Hanga setup:
Here you can see the corridor that leads from the hangar goes into the Warthog parking lot from d40 which then continues into corridors that lead to a stairwell. Down the stairwell and through another corridor you will meet another adjoining mirror of what was just described and another corridor which leads to the other two hangars and the rest of the ship.

Hangar:
Most of you have seen this in maps before. No different, except for that the two pairs of hangars are connected by the flight tunnels on the side, making flight travel from one hangar to the next, possible without leaving the ship or trying to fly through small corridors.

"Hangar to Lot" Corridor:
The corridor leading from the Hangar to the Warthog parking lot.

Warthog Parking:
From d40, leads into corridors (as you can see in the upper right corner).

"Lot to Staircase" Corridor:
Self explainitory.

Its coming along great considering I've been working on it on and off for a few days now.
Once I'm done designing the interior, I am going to need help with texturing, desiging the exterior hull, and importing into the game (because I suck at all three).
Questions? Comments? Concerns? Criticism?