Some of us humans have a propensity to modify things, and sometimes even improve on them.
The tinkered up Plasma Pistol (by humans) in Mothership Zeta is an example of this.
It was a must have as it did twice the damage as the standard issue plasma rifle, even if it was an ammo eater.
Firelance type stuff, by humans this time.
Even if the Alien blaster is a peice of Fallout Lore. (Random encounters)
Aliens are part of Fallout going all the way back to the beginning. Mothership Zeta went way overboard, but there was an alien crash site in Fallout 1 with an extremely powerful alien blaster. Oh, and if they're going to do an Area 51 DLC, there has to be aliens. The crashed alien ship in Fallout 1 had "Property of Area 51" printed on it. I wouldn't mind a powerful human creation like the Metal Blaster, but alien weapons will always be most excellent.
