Destiny’s Original Story is a Lot Different from What We Got
An interesting and now deleted Reddit post shed some light on what Destiny's story could have been, and what we've read sounds a whole lot more interesting than what ended up in the final build.
IGN has the low-down on the post, which mention a character named The Crow who would have taken the place of the stranger. The story takes a few sharp turns in this new narrative, saying that "the player learns that there's something wrong with one of the group's senior members, The Speaker."
Eventually the player would learn that "the Traveller – the person responsible for stopping The Darkness – is also the cause of The Darkness. In this version, The Traveller transports The Darkness to Earth with him, bringing on the collapse of The Golden Age, infecting Earth's technology to a point where it nearly wipes out all of humankind." The story would lead to the Moon, where a super weapon capable of turning the Traveler into the Darkness again would have to be stopped.
Now that makes a whole lot more sense (and sounds a whole lot more interesting), than what we've experienced in the actual game. Maybe these are story elements that will come later on, and maybe this is just a spoiler post disguised as a "what could have been," but we won't know that until Bungie sheds some light on things.