The leak was passed along to IGN including concept art and story details.
Post-leak, Bungie (the creator and former developer of 'Halo') confirmed the leaked document as having been prepared by a commissioned advertising agency.
As quoted by IGN, Destiny's "story begins seven hundred years from now in the Last City on Earth, in a Solar System littered with the ruins of man’s Golden Age. A massive, mysterious alien ship (the Traveler) hangs overhead like a second Moon. No one knows where it came from or what it’s here for, but only that it’s our protector. Meanwhile, strange, alien monsters creep in from the edge of the universe, determined to take Earth and the Last City. We are young ‘knights’ tasked with defending the remains of humanity, discovering the source of these monsters and – eventually – overcoming it."
Unfortunately, despite allusions to 'Star Wars,' and an accessibility fit for all ages, nothing gameplay related was revealed.
A previous leak outlined four titles for the franchise with release dates spanning on to 2020.