"According to the leaked document Destiny will be set seven hundred years into the future where the human race has become a rare species with a single city on Earth being their last refuge.
Suspended above the city is a giant alien spacecraft known only as 'The Traveler' which apparently protects the city, however little else is known about the craft or the alien race that placed it there.
The villains will be another alien species which is apparently creeping into the galaxy with one mission - to wipe out the last remenants of the human race.
Gamers will play as 'Knights' whose task it is to explore the galaxy all the while working together to try and defeat the creatures which seem intent on destroying the last city of Earth."
Many have speculated this game to be a console MMO, but Bungie is keep denying it. It seems now though, the game will only have some elements of MMO for CO-OP rather than full blown MMO on console
Leak & Artwork: http://www.t3.com/news/bungies-destiny-ga
Bungie.net confirmation: http://www.bungie.net/News/content.aspx?t
Original leak story is published on IGN, but I avoid their site wherever possible.