Anyone noticed from the trailer how the film might follow the same story structure from the first film?
Person A, who was involved in a fight with (the remnant of) the Empire and knows a terrible secret about them (R2-D2, Finn), crashes on a deserty planet. There he meets Person B (Luke, Rey), who's sick and tired of living on said deserty planet and wants to go on an adventure / leave it. The Empire tracks down Person A's location, Person B's place gets destroyed by the Empire as a result. They're now forced to escape the planet and they meet Han and Chewbacca, who take them off the deserty planet after a short exciting fight scene. Meanwhile, there's Person C (Leia, Poe Dameron), who's been captured by the Empire under command of Person D - who has a mask and a morphed voice - (Vader, Kylo Ren) (Twist might be that he is related to Luke?). Person C is manipulated into giving information to Person D, and he is forced to see his planet get destroyed by the secret(?) superweapon - which has a giant laser and a long trench (Death Star / Starkiller Base). Person A, who's now been trained to use the force and / or a lightsaber, fights Person D but loses (dies?). Person B is sad of this loss. The film ends with a massive dogfight, where the rebels have to destroy the Empire's superweapon. Superweapon gets destroyed, huge explosion, big celebration, cue end credits. We don't find out the exact identity of Person D and while he *might* have disappeared (sorta-kinda cliffhangers for the next movie), surprise surprise, he returns in the next movie!
Again, just a mostly silly theory. I might be looking too much into it and I see its holes; I don't know where all the stuff on the forest planet would fit in in, for example (place where Finn learns to use the force and / or a lightsaber, I guess).
Also, notice how in the very first shots a starfield gets wiped away by Rey? Maybe we don't get the traditional pan-down after the opening crawl if the first shots of the trailer are also the very first shots after the crawl, although it seems unlikely.