I'm not so sure this is (would be) true. Full service towns might be few, but there would likely be little enclaves of small numbers of people everywhere.
I think that people would be more likely to consolidate small settlements into larger ones, and the isolated hermits and very small villages would often be wiped out. Shady Sands was about the size of Megaton, and had a good wall... but was still constantly attacked by gangs and an unending stream of Radscorpions.
That aside, I don't think I'd want them to render all of that desolation. FO1 didn't even dop that to any meaningful degree. I'd rahter have them use the resources to build more playable areas, with more encounters and more things and buildings to explore.
Basically, it would allow one town to be a weeks walk from another, through a destroyed and abandoned landscape that looks like the abandoned parts of http://www.time.com/time/photogallery/0,29307,1864272_1810098,00.html ~but bombed. Mostly empty, but still dangerous, and prowled by predators (both four footed, two footed, and three footed); It would simulate in full 3d, the wasted cities you can find bits of in FO1. It would also be possible to fast travel past them (as you do in FO1), but not without risk of attack, injury (stumbling, cuts, and falls), radiation sickness, extreme thirst [IIRC if you went into the wastes without a canteen in FO1(or was it FO2?) you'd get dehydration damage].
*Endless rows of bombed out suburbia, damaged apartment complexes, strip malls, and industrial parks would be good candidates for procedural generation I'd think, and could be machine produced in whatever quantity needed. Giving the wasteland the true feel of endless destruction, isolation, and the possibility for strange anomaly from the very generation itself, as well as a bunch of hand made encounters peppered throughout (and set to only ever appear once in a game).