The Beatles were good for their time. In a couple generations, I think the Beatles will be regarded as we view the jazz artists. They'll be respected, but will have a much smaller, refined following, and not as many people will care.
I really disagree.
I don't mean that they'll be any less respected. If anything, they'll still be more respected than modern bands and future bands. When you think about it, older music is always respected at a higher level. Classical > Jazz > Classic Rock > Modern; as far as popular respect goes. I know I skipped a bunch of genres....but I just wanted to show that age and antiquity clinches a musical group into a place of reverence above everything else. See--The Beatles are just a drummer, two guitarists, and a bassist. I bet you could assemble together the greatest lineup imaginable, playing the same instruments, and it is literally impossible for them to be "better" than The Beatles in the public's eye.
But my main point is that while The Beatles will be held at a higher state of respect, popular culture and media will steer the public in a modern direction, as it always has. Since all those that were alive during The Beatles' career will have died, you will no longer have people listening to them for nostalgia's sake, and their fans will drop substantially.