After a second viewing, it doesn't look like the new boss henchman is Flynn. What looks to be a facial scar is actually a mole of some sort and Flynn didn't have that.
Also noticed in the trailer that when Drake had the torch in the ruins, he was shooing away those spiders that your player avatar could turn into for the mp portion of the game.
Based on the trailer it looks like the locations are:
Intro>Drake in Suit>French Chateau (no ring on Drakes neck)>Old Luxury Liner>Old lady's manor (ring on Drakes Neck)>Syria>Airfield>Plane on Takeoff/Midflight/Crashing>Desert>Lost City of Ubar>Ruins beneath Ubar>Atlantis (likely with lots of water and greenery to contrast the desert theme).
Drake obviously has to leave everyone behind in the 'I can't get on anything normally' transition to the plane and some or everyone joins up with him later I'm guessing.
This also leaves room for a Tenzen type character to help Drake when he's on his own because it would otherwise be lonely on this large stretch between the crash and the lost city.
Bad guys aside from fodder and likely MP skins are black guy with rope, The guy that looks like Flynn, Gotter (guy that shoots Drake), Diabolical Warlord, and wealthy old lady.