The following BF3 gameplay trailer is actual in-game footage for Battlefield 3's single player. Granted, it's a teaser trailer for the actual trailer. Yes those exist. In it U.S. Marine Sgt. Blackburn must enter the city of Tehran in Operation Guillotine, a joint operation to capture key members of the PLR leadership.
I can't wait for the actual trailer, kind of like I can't wait for the game. Battlefield 3 is set for October 25, 2011.