The Assassin's Creed franchise has always been friendly to conspiracy theories, so it's not surprising that Assassin's Creed III will deal with the modern-day Mayan Calendar theories. The theme also ties-in well with the GameStop-exclusive Mayan Ruins DLC, in which players will do some (boring-looking) platforming to retrieve a serrated sword.
Today's Assassin's Creed III trailer, amazingly, does not show gameplay and colonial locations that have been seen in dozens of other trailers. Instead, Ubisoft has practically given away the main story arc of the game, showing gamers exactly where Desmond will fit into things.
The video, seen below, could very well be the intro cinematic for the game. William Miles (voiced by John de Lancie) narrates and recounts the previous trials of Desmond, his son. Desmond has been captured by the Templars and used to obtain a valuable Piece of Eden. Now, with December 21, 2012 approaching, the world's fate rests in Desmond's hands.