I'd like to see some larger scale weapons.. not strictly handheld ones. Like a turret you could jump into to launch an artillery strike on an area; where you suspect players could be. Or a button you could push to explode a gas canister that temporarily poisons an area. I'd also hope the intended victims would have some forewarning to give them the opportunity to flee the area; potentially putting them at risk of being detected as they run away.
As for handheld weapons.. I think some randomly generated stats could also work. Have set models for X amount of guns that behave in specific ways. Then add a random variable to their stats, allow some to perform better or worse in some areas; perhaps like Borderlands did their weapons.
Having huge varieties of types and styles of weapons becomes a bit pointless after a point. Unless, of course, there's going to be wider changes to the 'futuristic' nature of guns, such as rail guns, lazers, homing bullet arrays, poison/tracking darts, nanomachine grenade launchers, napalm throwers, sonic cannons, remote or lazer controlled rockets, plasma lobbers, exploding or tracking drones, tonic goo launchers, spinning blade throwers, electrified nets ... and that's not considering melee weapons.
After a point, how you get the job done becomes a matter of entertainment rather than efficiency. So it becomes a question of the intention of having a wide variety of weapons, and whether that purpose is being appropriately served. As an example, I love the idea of being able to shoot a bunch of spider drones towards an enemy, and laugh my backside off as they chase him across the battlefield. But, it would be much more efficient to simply shoot him in the head with any standard gun.
In case it needs to be stated: I much prefer to be highly entertained than win a battle.