It's a problem in all mediums. Nick Carr is the latest to opine on this particular topic, he does so with his usual, uh, panache. ;) Linking to a NY Times article that looks at the same topic, he wonders, if, "An even bigger open question lies on culture's demand side: As the flood of free, immediately and universally accessible user-generated and -filtered content grows, will the audience for well-crafted work shrink?"
The answer is not yet clear, but I'm not super optimistic. This is the role that traditional media have always been good at, when they are at their best. Is there an economic model that will allow this to continue? The jury is out...