In a post on the Obsidian forums, Feargus Urquhart commented that he would love to make another Fallout game, and that Obsidian might be toying around with the idea of their own post apocalyptic IP.
As for future titles, I would like us to continue making both Fantasy
games and games placed in other genres - like Post Apocalyptic and
SciFi. A number of us have been toying around with the idea of a Post
Apocalyptic Fantasy world. There are a number of campaign worlds out
there that explore this idea and I think a really cool video/computer
game could be made within a world like that. While we couldn't go with
the campy 50's feel of Fallout (campy as in the Pip Boy look, not campy
as in culture references), I think the tension created by having all
the different fantasy societies trying to scrape by and rebuild would
make for an interesting world to explore. As for a straight SciFi game,
I don't have an real specific ideas about what we might do just yet. I
know a lot of people around here love 40K, so I was thinking of talking
to THQ at some point about whether they would like to a 40K game that
is more RPG than RTS.
Finally, I should probably talk about the twin gorillas in the closet.
I'm sure there's a correct analogy in there somewhere, but that's what
came to mind. Anyway, I'm speaking of the the KotOR3 and Fallout
gorillas. Both of those are games that I and everyone else here at
Obsidian would love to make. I don't know if we will ever get the
chance, but I do continue to talk with LucasArts about what might be
going on with KotOR3. As for Fallout, like I said, I'm not sure if
we'll ever get the chance, but I know that I'd love to make another
Fallout - plus, I think Avellone's already designed the next 12 of them.