Tell me your definition of dead and I will get you to answer your own question...
Personally, I believe no music ever dies. It's born and then it's there forever for anyone to just listen to. I don't care how much money there is in it, or what's number one on the charts or even if it's made anymore. If it existed...it's still here. It's just up to you whether or not you like it enough to go find it or make more...
I do see a certain degree of resistance to new artists in rock music. Most of the bands rattled off in this forum are at least 10 years in, and have been established, successful acts prior to the current year (had better album sales for past efforts as well.) The problem is you get the hardcore fanboys who will NEVER listen to anything other than their core favorites. And then you've got the underground kids who will only dig a band UNTIL they get a certain degree of success, then they throw them under the bus as "sell-outs."
I think this has always been the problem with rock music though. It's born of rebellion and has a stigma that once you become successful, you become part of the established order and must be rebelled against.
As long as we don't start singing about cash/cars/hoes we'll be alright though (notwithstanding Nickelback...bastards)
OMG, no it's not dead, you just have to search more for an underground bands