Rock music has been around since Elvis, and has gotten better and better since, giving birth to such miracles as Zeppelin, Guns n'Roses, Sabbath, the list goes on and on and on...
There are people who have grown up with Rock music living all over the world, including South Africa ("Hi,Mom") who are so disgusted with hip-hop and pop rising up in the last decade or so and claiming to be "the next big thing".
In my opinion Hip-Hop is the salt of the earth (did I say salt? I meant scum of the earth)
Thankfully there are bands that have refused to go down without a fight (thank you Green Day, Foo Fighters, Linkin Park etc.) because Hip-Hop is all fine and good if you are young and grew up with it. After all, we grew up with Rock. But then there are people who stand around, not a thought in their heads and go up to their nearest friend who is playing Hip-Hop and think, "OOOOOOOHHH... Preety". The Hip-Hop has built up its followers because of peer pressure.
Don't get me wrong, though. I listen to a little Eminem occasionally, but if you ask a Hip-Hop junkie is they ever heard of Motorhead, they would probably think "Oh, he's talking about a car!"
So if you asked me where Rock and Hip-Hop would be in 10 years, I honestly think that we would have an entire world's population of Hip-Hop junkies who like their music just because society demands it, and a few rebels here and there who remember the Sex Pistols and smile.
I hope it doesn't come to that, but I guess we will have to wait and see what happens.