I don't believe there are more than 2 layouts, one in the black hall, & one in the White hall. Correct me if I am wrong.
It's varied a little over the last few years, I think. Sometimes there are smaller layouts in the White, and occasionally there are 2 of them in the one location. I seem to recall a small S-Gauge point to point (or maybe a switching layout) next to a modular O-gauge layout one year (may have been a modular S-gauge there as well at some point)
Same thing for Black with 2 layouts sometimes, I believe, but this is not the case when one of the much larger groups like National Capital Trackers or the Flower City group from upstate NY sets up, they generally take the whole room.
There was at least one meet where there was a layout in the smaller room to the left side of Orange (side room where the Forum's own Sean Marchev from Doherty's Trains used to setup).
One recent meet had a decent sized layout with kids stuff (Thomas the Tank, neat accessories/scenes, etc) in Purple.
Sorry none of this has any specifics about this coming meet, but it's various other places layouts have been set up in recent memory.
-Dave