It feels like one of those periods right now.
Seems like rock hasn't had an explosive movement or scene since NYC/London skinny jeans in early 2000. In comparison, right now feels a little like what 97-2000 was to grunge and alternative rock. I swear I even read the "2008 was a slow year for music" pronouncement from several music mags, but I can't remember which.
And it hasn't just happened to the hipsters. There are legions of unnecessarily quiet pre-teens and teens right now with little to scream at. But then again, will anything ever again compare with the H-bomb that was Britney, Xtina, Backstreets, N'Sync, etc.? Miley feels like a postscript to all that, and she already seems to be on the wane.