I took a look at a recent trailer (I'm so going to see this on opening) and caught these.
The PSC in the background has an M4 (or other similar AR carbine) with a rail system, PEQ-2, and M203.
Another shot I got of the above M4/M203. It's quite blurry (and a hard one to get), so exact ID isn't possible yet. But the profile is definitely M4/M203.
Beretta 92F or 92FS
Edit: Took a look back at one of the older trailers and got this shot.
The PSC on the right has an M4/M203 and the one on the left has what appears to be a Minimi mocked up as an M249. On the Minimi, I'm guessing mock-up by the really fake look of the heat shield and what looks like a synthetic butt stock.
