I used to dislike "nu metal" quite a bit; that cookie monster sound is absurd. But good songwriting, I feel, knows no boundaries and, even hip hop music, when it's done very well, can be extremely good. The stuff Dr. Dre has recorded, in my opinion, was fine work. The rock-rap combo is not new, Faith No More brilliantly executed it with "Epic" and, again, when done right, continues to be totally amazing. I was a huge fan of Hybrid Theory by Linkin Park ten years ago. One of the only records in the last 15 years where most of the tracks on the disc, I liked (Fallen by Evanescence is another). Limp Bizkit came off, to me, as music you go through your Sophomore year at college listening to but not really serious the way, oh I don't know, Rage Against the Machine was. RATM, while not always my cup of tea, recorded a lot of serious rock-rap for which the genre, I'm guessing, was intended.
I honestly don't think Nu-Metal is "dead" either, to answer the original question. And honestly I will take a nu-metal song over more mainstream acts like Nickelback or the Kings of Leon any day.