I think there are some bands that have a sound of there own. Creed and Nickleback being a few of them, I guess there are bands that have been around for a while, although not as long as U2, because of there unique sound, like The Red Hot Chili Peppers. Bands like this arent really nu metal, they're like hard rock. I think of bands like Project Wyze(from my hometown of Sudbury, unfortunatly) as nu metal bands.
I think there are some promising newcommers to. I like Incubus because of there fusion of all kinds of different styles of music, like Jazz and Hard Rock. I think that kind of music will be even bigger in the near future.