Admittedly I've been very lazy as far as progressing on this one...
The main portion of the playset houses the Mission Monitor Room. In the center is what is basically a version of a "TroubAlert".
To the left, is a super-villain data-base and to the right is the JLA Communicator:
Lots of computers and viewscreens, I know, but that's basically what goes on during "monitor duty" .
All of the larger screens are interchangeable.
To the left of the super-villain data-base is the JLA Transporter. The viewscreens off to the side in this room are of the more cosmic nature.
Multiple earths, dimensions, yada yada. It's actually a Transporter/Transmatter Cube, which the JLA uses to travel to other universes like Earth-2.
Had to consolidate for space. The stickers and the exterior of the Trek transporter will most likely be altered.
Still work on the right side extension, which is the villain holding cells.
On the outside of the extensions will be the trophy room and the sickbay/lab.