It's difficult to declare the start or end of an age when you're living in it, but I totally did it dude. In 2011 I looked back and said, "I'm reasonably sure it's not just that I'm getting old, but it seems like we've entered another dead zone. 2009 is the start of the dark age." It's the third such interregnum since metal began as a distinct genre in the 70s.
So allow me to quote a "metal is dying" article, and specifically none other than Cradle of Filth's Dani Filth: "I think the last big year that everyone’s talked about was 2008, the last big year that people across the metal scene said that they bought a sports car or went out and did big shows." Whether there is a shift in culture that will prevent another resurgence, I have no idea - although thanks to the internet, it's pretty hard to scare people with your subculture these days, which is a big negative for a subculture that wants to seem scary, or even be separate at all.
As an aside, have you noticed the recent proliferation of articles and blog posts by grown-ups complaining that Kids Today Aren't Cool? I'm not going to bother linking to one because if you care enough, you can find one on your own. One in particular made me laugh, whining that he saw 20-somethings in a Brooklyn bar listening to Justin Bieber. First, I don't recall a shortage of clones with mass-produced taste when I was growing up in the 80s, so I'm not sure what's different here; second, these articles boil down to "Hey man, if you don't conform to the same music that I (a guy your dad's age) like, then you're not a real rock n' roll rebel!" If only these guys could hear themselves. If rock is dying, no wonder!