Zach Snyder (the director) and Frank Miller recently did a Q&A about the upcoming movie
300, revealing that NIN will not feature in the soundtrack, only the preview.
Click here to read the interview. Snyder and Miller do state that NIN "embodied the sort of attitude of the movie and that's why we used it for a lot of the trailers," which is cool. Thanks to Gustavo Natanael for writing in with this.