"I'm starting to hate myself a little bit. How could I be so damn late in finding out that there's a movie coming out based on Kurt Cobain's biography. What kind of a hardcore fan am I?Anyway, I know I can forgive myself for that in time. So according to the website where I found the information.
* The movie is based on Charles Cross's biography of Cobain, "Heavier than Heaven", which would likewise be the title of the movie.
* Courtney Love, executive producer, has said she wants actor Ryan Gosling to play her late husband Kurt Cobain in a film. 
(Well for those who don't know her she's the widow of Kurt Cobain and the mother of their child Frances Bean Cobain)
* Courtney who seems to be a fan of Scarlett Johansson wants that she portray her.
Well, I just hope Courtney, as executive producer won't make a trash out of this movie. But I SERIOUSLY DOUBT that the hardcore fans and loyalists would really appreciate the film, if up to now, the truth about Kurt Cobain's death has been a mystery for some and it's a fact that Love is being said to be involved in Kurt's death.
Now, based on Rollingstone Magazine pre-production has finally kicked-off, and the initial casts of the film aside from Scarlett 
Johansson and Ryan Gosling are:Justin Long as Krist Noveselic, Nirvana's bassist
Topher Grace as Dave Grohl, Nirvana's drummer
Cate Blanchett as Eric Erlandson, served as Singer, guitarist, and songwriter for Nirvana
Jake Gyllenhaal as Axl Rose of the Guns 'N RosesJack Black as King Buzzo, (Buzz Osbourne)
Emile Hirsch as Eddie Vedder, lead singer of Pearl Jam
Eddie Vedder and Emile Hirsch in San Diego 04/16/08Toni Collette as Kim Gordon, of Sonic Youth
Ron Jeremy as Tad Doyle, of the band TAD"
Source: iamstayingalive.blogspot.com