Don't hold your breath if you're waiting for a new Obsidian Fallout game as the studio says it's "Very doubtful" it'll get another chance at tackling that particular brand of the post-apocalypse.
Obsidian developed Fallout: New Vegas after Bethesda's foray into the series with Fallout 3. While New Vegas enjoys high regards from critics and players, both Bethesda and Obsidian have gone on to say that it's unlikely a development situation like New Vegas' will happen again. That hasn't stopped people from asking.
On Twitter Obsidian was asked (probably for nth time) whether there's a chance the studio will work on another Fallout to which the studio responded:
A picture of a magic eight ball responding, "Very Doubtful."
Obsidian and Bethesda have both commented on follow-ups to New Vegas many times. In an interview in July Bethesda director Todd Howard said it's unlikely to outsource development on major titles in the future considering how big Bethesda has grown. It recently opened a new Austin, Texas studio that's helping with Fallout 76.
Meanwhile Obsidian said several times that it'd love to work on a new Fallout: New Vegas but has been busy working on a new RPG for Take-Two's Private Division and is potentially considering getting acquired by Microsoft.
At the very least we will always have the Fallout: New Vegas that did come out. We ranked Fallout: New Vegas #13 on our list of best RPGs of all time. We also spoke with Obsidian at-length to find out how New Vegas came to be the cult classic it is today.
Funny enough I'm currently re-playing Fallout: New Vegas in anticipation of Bethesda's Fallout 76 coming out next month. You can read our Fallout 76 guide for previews, news, and trailers for more info.