I think there's more that two Fallout games that have been released, that's what I think.
That said, I do believe you are referring to FO3 and New Vegas. Assuming this is true, it's not gonna happen. Beth is (presumably) working on their next project, which it widely believed to be FO4. I'd much rather they concentrated on that, than the other two most recent games.
No... Not something I would want to see done. I doubt anyone who wants a redux would actually enjoy the game very much... the graphics are decent as is, but far from being the reason to play; and If they put all that work into a remake, they would doubtless tinker with the core of the game, or add fan-fiction ~as official canon... bad... very bad.
It would be enough to just run the game in DOSBox on a decent machine, and use a scaler filter on the game to smooth out the pixels.
*** Or do you actually mean FO3? That's not Fallout by any stretch. A redux of FO3? sure, why not?
There is no hi-res mod... not really; all it does is cram more sprites on the screen at once... The graphics are unchanged; same as they ever were, just harder to see.
I mentioned DOSbox's scaler filters because ~technically~ http://en.wikipedia.org/wiki/Image_scaling.