It depends on what Bethesda choose to do next. By that, I mean: afaik, New Vegas (and the forthcoming DLCs) are an offshoot of the Bethesda FO, they are the culmination of the original Fallouts, tying up loose ends and putting "Van Buren" to bed. Bethesda chose NOT to go with those stories and places in FO3, setting it eastwards. I have a feeling that Beth will explore THEIR Fallout Universe in FO4, with the Commonwealth, Pitt, New York, Toronto. But who knows?
Typing up loose ends? There were no loose ends tied up in New Vegas, but there were plenty of new questions raised. I highly doubt New Vegas is the last we've seen of the west coast.
Certainly, from the reception I've seen in magazines, websites, and my own intuition, New Vegas hasn't been as well received as FO3 was,and IS.
That's mostly because of bugs based on what I've read. Most critics seem to have enjoyed the gameplay/content, but were simply frustrated by the amount of bugs they stumbled across.
So I would think that it would make commercial sense for them to build on their rebooted FO3 Canon, not FO1/2/NV, even though the latter would please the die-hards.
What rebooted canon? All of the Fallout games (except BoS) are set in the same universe/canon. There was never any reboot.