The trailer puts you into a position where you have to choose your own path. Whether that be going for the stealthier approach and stabbing the guards, going head on and challenging the guards or use your magic to blink around and avoid them completely.
I sure hope other developers adopt a similar approach to their games. Such interactive trailers are successful in giving players a short action preview of the game.
Dishonored will be released for the PS3, Xbox 360 and PC on October 9.