I don't think rock 'n roll is dead by any means. The whole "music industry" is a shambles right now. So how do people who are writing and playing rock 'n roll go to get heard? No where, for the time being. Top 40 radio is more or less gone but Classic Rock FM is still alive and kicking. There just has to be someone to kick their door down and make them play the rock that is currently being produced. It seems to be a corporate problem where the suits are not allowing anything new, only the "classics."
All this Hip-hop, Rap and whatnot is never going to survive because it is simply not good enough. Young people are going to grow out of it because it is, generally speaking, so lousy and it makes you feel bad. Who will want to hear it when they are old enough to think and reason like an adult? Very few and then good old rock and the Blues as well will be making a big comeback. There just has to be a big shakeup of the "industry" so that it is not dominated by people who know little about music and care even less. We have to ditch these multi-national corporations and their clone execs and let people who love music back in.