Now, I'm not sure if this has been said or confirmed or whatever already but here's what I took a big notice to, during NV's First DLC...
Upon playing and finishing Dead Money, I realized the place called "The Big Empty" was mentioned... Quite a bit, in the end Elijah even goes as far to say
Spoiler
that there is tech such as Holorifles, Holograms, Pre-War Collars, and even... The highly wanted Ghost People Armour (That part got me pumped).
The Big Empty was mentioned a lot during Dead Money, but does this mean it will actually become the next DLC?
I sure hope so.
