The "Destiny" ViDoc is titled "Pathways out of Darkness" and sets the stage for the story of an Earth 700 years in the future where the last of humanity is struggling to survive. Here's the official description from Bungie.
Everything changed with the arrival of the Traveler. It sparked a Golden Age when our civilization spanned our solar system, but it didn't last. Something hit us, knocked us down. The survivors built a city beneath the Traveler, and have begun to explore our old worlds, only to find them filled with deadly foes.
You are a Guardian of the last safe city on Earth, able to wield incredible power. Defend the City. Defeat our enemies. Reclaim all that we have lost.
-The next evolution of entertainment - an incredible story set within a newly-imagined, always-connected universe filled with action and adventure.
-Create your character, forge your legend by defeating powerful foes, and earn unique and customized weapons, gear and vehicles.
-Unprecedented variety of FPS gameplay that redefines the genre breaks traditional conventions of story, cooperative and competitive multiplayer modes, combined with public and social activities.
Platforms for the release of "Destiny" is confirmed to be the Xbox 360 and PS3 for now. It is believed that Microsoft has a timed exclusivity agreement with Activision for the game to appear on its console first though. A release date has not been announced yet but it is available to pre-order from Amazon, Best Buy and GameStop.
One thing is clear from the video though is that Bungie is going to push social interaction in the game through other devices like smartphones.