This is larger than the scope of TTW, possibly, because it would require permissions and the desire from two other teams to do so...however, I don't think it would be too hard to implement (although I don't know for sure) - and would be IMO an amazing mod!!! So in that way it would be smaller in scope to get implemented. There is no forum connecting all 3 of these teams so I just thought I'd start getting some ideas to see what you guys think (the TTW team and fans) here.
So here goes: Imagine you are playing TTW and wish, man I wonder if I could play Project Brazil (http://www.nexusmods.com/newvegas/mods/45138/? by the Project Brazil Team) or DUST the Survival Simulator (http://www.nexusmods.com/newvegas/mods/57927/? by naugrim04)- I take no credit for these or any mods and do not plan to, I just want to propose an idea for a mod-
Well, playing either of those two mods would likely not be compatible with TTW and you probably wouldn't want to play them all together. But what about choosing 1/3 at the startup menu for the FONV engine? If you could choose or quit your game in one, go back to this menu, start up the engine to play one of the other 2/3 mods- that would be great!
Also, it would really vamp up popularity (and thus testing) for all 3 of the major mods (not that DUST is major yet in any way and also has some mixed reviews because it makes MAJOR changes to Fallout New Vegas so its in many ways a different game with different gameplay).
The 3 mods could each have their own Fallout New Vegas **** (TTW, PrBr, or DUST) suffixes for folder names, with a unique Fallout New Vegas exe for each in its own folder, eliminating the problem of where to store Data files- you could even have their own My Games/subfolder to avoid the problem of different Fallout and Falloutprefs ini files. There would have to be some separate (but similar) launcher to the normal New Vegas one that would combine all three and then reference each folder.
Maybe its too much work/too difficult/ or too big of an idea- and little interest- but maybe not! What do you guys think?
UPDATE: MO would be a better soultion! But of course. 
 D'oh.  I am still very beginner to MO but if I learn how to get this all going I may try to provide a basic tutorial here for people new to MO (although there are guides available so it shouldn't be too hard- S.T.E.P. Fear and Loathing, Gopher's MO vids, etc, none of them are directly for TTW, which IMO would be much preferred)