I don't think there will be drivable vehicles. That doesn't mean there won't be any (perhaps as a reward for a kill streak, you can call in a tank or some kind of ship that hunts down your enemies for a limited amount of time).
In the video where the guy uses the AC-R Eclipse to turn invisible, you can distinctly hear in the background a developer saying the SMAW returns as a secondary weapon. Also, when the player dies, you can the a loadout on the upper right screen having a SMAW as a secondary weapon.
2 shots is good. Maybe give it a chance to have a reload animation.
Proud Student of the University of Pennsylvania MWR: 4893-7948-2427The Conduit: 2836-7869-1737