Via GamesRadar, this is the leaked first trailer for Assassin's Creed IV: Black Flag. In the trailer, a grizzled pirate describes Captain Edward Kenway.
"There was a time I thought myself the deadliest scourge of these seas," the pirate says. "But this man..."
We then see Kenway hacking, slashing and doing his assassin thing. The trailer ends on the silhouette of Kenway.
It also states Assassin's Creed IV will be out October 29 for PS3, PS4, Wii U, Xbox 360, PC and "also next-gen consoles".
GamesRadar (trailer has since been removed) [YouTube]