Interesting coming upon Gerard's item below, but in today's "Hollywood Reporter," Paramount Vantage has included a CD containing Michael Brook's original score from "Into the Wild" (with guiter from Kaki King) as well as the four Eddie Vedder songs they're pushing for Best Original Song.
As for eligibility, there should be no concern for the reason Gerard points out, but also, this is the same kind of situation as when Yo Yo Ma, for instance, offered his cello work to the compositions of John Williams or Tan Dun.
Vantage was totally on top of things last year with the "Babel" soundtrack, and obviously, it yielded a win. I don't think Brooks' score is as likely, but it's worth noting that the campaign is on the hunt again.