Would be GREAT if Dev. Would implement in dlc new weapons types like some more machine guns,rifles,like winchester, grenade launcher- of corse with Automatic machinegun launcher - like in Fallout New Vegas. Also ammunitions should be craftable and they also should add different ammo types. Thats it.
For me, the game won't be complete until it has been crammed full of 20th century weapons again. At least the weapon modding does give it a bit more variety than Fallout 3, although sadly few weapons are as customisable as the pipe guns.