A few years ago there was a interview with Obsidian in which they said they would be happy to make another fallout if Bethesda let them.Now that Fallout 4 is finally out,by the way it's incredible.How about fallout made by Obsidian?
Here are a few ideas:
new setting-they already said that most likely it will take place on the west coast.How about the Boneyard?Or better yet the locations from Fallout 1/2,I think it would be incredible to experience that world in 3d.
bring back the karma system-They absolutely nailed the karma system in nv so why not bring it back?
Enclave-seeing as most of the fallout fans have only played the 3d ones,we haven't really seen much of the enclave.In f3 they were bad guys no question,but with the "grey" karma system in nv,maybe we cand get a new look on them.
The music-keep the vegas\western themed songs and bring some back from nv
What are your ideas?

Don't you go mentioning that idea around here!
The mob will chase you out sir

No thanks, I hated NV enough to give it away for free and I'm going to need a bethesda game to play years from now between the Es 6 & Es7 gap.

There's quite a few ways that 4 trumps NV anyways and it hasnt even recieved free updates or any DLC yet.

I'm all for a NV2. I enjoyed New Vegas and thought they nailed a lot of the downs of FO3. I'm loving FO4 but would so love to get NV2 as I'm missing the dark humor and karma.