I do hope I'm wrong. Social and cultural history is an amateur hobby of mine, and I hope I live long enough to see exactly what the long-tern cultural legacy of the Beatles holds.
People always assume the here-and-now is forever. I can imagine that in the future, school kids will groan when they have to spend a few weeks covering the Beatles in some music-appreciation class, the same way they suffer through reading 'Romeo & Juliet'.
In a century after all the copyrights have expired who knows how we'll view the Beatles (or recorded music as a whole)?
As for Elvis, ...