In the way that most of the world is a big take-all buffet of free stuff laying around for the main characters to scavenge over, yes.
In the way of being desolate, I suppose being out in the wastes minus being around raiders, yes for portions of the game. NV does better than that though.
Not to the level of I am Legend however.
Both have hidden dangers lurking around in dark corners that want to eat you.
I don't think than any ideas were shared. It's just very roughly in the same genre theme.
In no way, shape or form does NV do "desolate" better than FO3 (IMO). If there's anything that FO:NV
doesn't do better than FO3, that's it. Sure, you're alone in the Mojave, but it completely lacks the emotionally desolate vibe of FO3.
And
I am Legend is just a different animal altogether. The movie is all about Robert Neville, a sort of character study. From the player's perspective, the Fallout games are about the wasteland and its inhabitants. You can't really say that the Fallout games are driven by the character of the protagonist, since he/she has no more substance than the player gives them. The wasteland is the star of the show.
And the NYC of
I am Legend isn't just desolate, it is devoid of intelligent life.