Okay,i've played this game many times have done pretty much all the endings but Mr.House (working on this one right now) & the NCR (I'll never do the NCR ending because i hate them) I've looked up a lot of these areas and pretty much they do fall within the area of Nevada on the wikia and they areas id really like to go to or hoping to see in the up coming DLC are the following:

Boulder Dome ----> http://fallout.wikia.com/wiki/Boulder_Dome (here's the link if you'd like to look it up)
Reservation, maybe i really hate getting rad sickness and this place has well a very high chance to getting it ----> http://fallout.wikia.com/wiki/Reservation
The Glow, it was pretty cool back in fallout 2, id like to see what it looks like in 1st person though but doubt it'll happen.
Area 51 hell yeah its the only place i can think of that has a lot of "old world delight" plus maybe Aliens(?) who knows
The Divide
The Big Empty just because it sounds pretty cool bada** and the Holorifle is the best item ever even if your character is speced in guns (it svcks though if you cant really hit the ghost people with it ), I really do hope it'll show up in "Old World Blues" if they keep that name it'll fit pretty well
(here's the links)
http://fallout.wikia.com/wiki/Old_World_Blues
http://fallout.wikia.com/wiki/The_Big_Empty
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last but not lest id like to go to the Tibbet's Prison ----> http://fallout.wikia.com/wiki/Tibbets_Prison

All those places do fit within the American southwest (Arizona, Nevada, Colorado, Utah).

Other than that and plus awesome new guns and other ways to piss off the NCR for the luls what places would you like to see?

I would not mind area 51, but no aliens. It should just be an abandoned military base with some cool weapons.
You other ideas are pretty cool tho. I would not mind seeing some of those locations.

Yeah true, but at lest it shouldn't be abandoned, i think it should have some like robots some radroches and a feral ghoul(all the types) plus afew glowing ones....but not holograms sense the only place there are those is the Big Empty (i'm guessing broken or hardly working) And Sierra Madre (fully working version) but in fallout 2 in a random encounter you do run into a UFO that belongs to Area 51 so with that there should be at lest some weapons/armor or even one in cold sleep(dead).

Have a thread for suggestions already: http://www.gamesas.com/index.php?/topic/1162622-future-dlc-suggestions-7/
And Then we have another: http://www.gamesas.com/index.php?/topic/1174359-what-do-you-hope-to-see-in-the-upcoming-dlcs/

The Glow would be really uninteresting though, what you see in Fallout 1 is what you get, ain't nothing else down there.

This isnt suggestions, this is only what we would like to see mainly places if they do show up in game that'll be grand other than that oh well.

Use one of the topics linked above please - thanks.