I agree with Blind Fellow, he killed himself. He couldn't deal with commercial success and the torture of heroin withdrawl. He wanted to kick heroin but couldn't deal with the physical pain of detox. I think he wanted his music heard but wasn't prepared for the instant riches or fan worship. Remember how about 2 weeks before he shot himself he tried to OD? It was a sign of what was coming...a "successful" suicide.

I think he was a lyrical genuis, but I think that with that also came an insane genuis, or at least someone who was emotionally and mentally troubled. (Obviously) I'm stealing a quote from Fox Mulder in the X Files when I ask, "Isn't it reasonable to say that someone with heightened intelligence may also have heightened psychosis?" Or maybe this all makes sense because I'm stoned...

And I don't think that we should forget the OTHER members of Nirvana who were also responsible for the band's greatness. Dave Grohl has proved how influencial he was with his further success with the Foo Fighters and Queens of the Stone Age.