As we type these words, we're listening to the original soundtrack for Destiny, which has just been released on iTunes. Bungie confirmed the release of the soundtrack on Twitter, explaining that the game's score is "available now at a discount to celebrate its release," with the album currently priced at £7.99 / $9.99 / 8,99 €.
The title song by Paul McCartney - Hope for the Future - isn't included in the soundtrack (that's the one that plays while the credits are rolling). You can hear that one here while the soundtrack downloads from here.