I personally think "new" fans are fans, but not to the same level as older fans, in terms of love of Fallout and knowledge of lore. I am a "new" fan, and I think that that description is perfectly accurate.
I am not trying to denounce new fans, because I am one.
I'm a new fan in terms of series introduction (Got Fallout 3 around when it first came out), but I think theres 2 major splits in the fan base, and a 3rd 'middleman' group. The two major groups are are the Old vs New, then the minor group (Which I fall in) only cares about lore and sensible design of the game world. I don't LIKE the old games in terms of core gameplay, but as long as the game brings proper portrayal, understanding, and little if any abuse against the lore, I'm okay with most gameplay styles, so long as keeps some semblence of it's roots as a roleplaying game.
As for New Vegas, I'm on an extended hiatus since my PS3 moving joystick has a forward moving bias (It's 3 years old and has extensive use). But my complaint about F3 and NV is this, when I play New Vegas, I wish for more exploration, when I play F3, I feel like there is so much to see, but nothing to actually do. Exploring for explorers sake gets tedious.