A user from TFG2 spotted the difference in the scene where scorponok vs jetfire. (Comparing new and old trailers) Seems like they revised the weapon for Jetfire. Old scene New scene
the trailer are jsut shots in the movie that looks almost completed...since its cgi, they can add/remove stuff (George Lucas revisits many scenes and changes them for dvd release aka Star Wars Prequals) another scene change was the early shots of The Fallen crashed down in fire had only soldiers being blown away, but the new TV spots had the autobots in it as well being blown back... early scenes had optimus being kicked in the air with his blade in dark color, but newer trailers add the orange/red color to his blades...