Musicians in all genres are running out of ideas. Compare the music of 1968 and 1978 - they're completely different. The same applies to the music of 1988 and 1998. But the rate of change is slowing and becoming less substantial. If you played me a piece of music from this decade that I had never heard before, odds are that I wouldn't be able to pinpoint the year.
Rock and roll is dead, spent. Its ethos is simply not relevant anymore. Metal, like progressive rock before it, is now wallowing in its own retarded excesses, forgetting to actually, you know, be GOOD. I mean, at least I'm able to LAUGH at hair metal. This shit is just...depressing. And as for punk rock - it doesn't exist anymore.
To find anything worth listening to, you pretty much have to avoid major record labels. For some fucking reason, utter shit is what's selling right now. It didn't have to be this way - but that's the way things are happening.
The new form of popular music will probably come in about twenty years. It'll be something very simple and modular - something that has a lot of room to be expanded upon. It'll likely have more in common with hip-hop than it does with rock and roll. I probably won't like it, but then again, rock and roll started to suck the moment it became a "respectable" genre that people in their 40s and 50s could listen to. Old people aren't SUPPOSED to approve of new things.
Now, there's always been good music and there's always been shit. A lot of shitty bands become popular - this is nothing new. Unfortunately, what I'm NOT seeing is a large number of new bands bringing something fundamentally new to the table. There are a few bands that present a new take on old concepts, but nothing that comes right the fuck out of nowhere like, say, Bob Dylan, Frank Zappa, or Devo.
As it stands, originality in music is dead, in my opinion. I could be wrong, but I've got a strong feeling that history is going to prove me right.