At every point in the last 60 years at least, a variety of genres has been popular at any given time.
.'. this is a silly thread
Seriously though, as I see it, I can't see any of the major genres dying out any time in the near future, although saying that, another '69, '77 or '91 could be just around the corner for all I know. Alternative music has become popular recently in a way that we haven't really seen since Nevermind came out. The popularity of people like The xx, Fleet Foxes and Vampire Weekend is evidence for this. Folk revival seems to be popular here in England at least, with Mumford and Sons becoming one of the biggest bands over here, playing pretty small venues less than a year ago. I heard somewhere that sales of metal are comprable to those of rap, however, its not going to reach #1 on the radio any time soon.
All that said however, my money is on trad soul/R&B revival. Its slowly coming back into fashion, with Cee Lo Green, Janelle Monae, Sharon Jones and the Dap Kings and others. It will possibly combine with NPR friendly indie pop and create some awesome hybrid thing (we have already seen Of Montreal collaborating with Janelle Monae and Solange Knowles, and Monsters of Folk with the Roots)
