I don't think that would make for a good Fallout game. You'd need more Contrast, a Conflict around something important next to roaming around in the Wilderness. Sure, one could have some Factions, some known and some new, settle in Kentucky and fight it out over the big fat Bunker full of Gold. Then again, Gold is a rather useless Material. It wont corrode, which will give it at least some use in the wasteland.
Other then that, a Gold Bar would only be useful if i threw it against some Raider's Head really hard. A Shotgun would be more useful in that World.
I would like to know what happened to the Wastelands after the respective Games. If there's a Game in Boston, maybe we'll see some Lyon's Brotherhood scouting with a Vertibird. Maybe they'd be a minor Faction with some sidequests to find out about Technology from the "Commonwealth" that was mentioned in Fallout 3.
Same thing would be possible if a game where to take place somewhere east or north of NCR Territory. I figure that the NCR and the Brotherhood do well and wont get destroyed in the canon.
In a new game, the D.C. Brotherhood or the NCR are merely scouting about and at the end of the Game will be thankful that the Player has killed all the bad guys and they don't have to gear up for another bloody War.