I gave up on Metallica when their self titled album came out (damn you Bob Rock). When they freaked out about napster I was surprised but it kinda makes sense with their switch to pop.
There's other avenues of generating funds, artists such as Moby have shown us that by making huge sums from advertising. I know, not everyone can do this, but hey, not everyone can be a movie star, exotic animal breeder or a rock star.
I've seen figures saying that since file sharing sales are up for music sales, and I'm sure there's figures out there that state the opposite. I do know I downloaded music via Napster I wouldn't have bought and other music that I never would have been exposed to as it just isn't played on the radio. Also there's the live performances, the odd cover song and stuff that just isn't being produced anymore.
Some how I can't see file sharing going away, I can see it going underground or servers being moved to countries where there are lax or no copyright laws where the RIAA holds no ground.