Thoughts below with some speculation and spoilers from the trailer.
At first I thought Finn was going to be the star but after the poster has Rey literally at the center I'm not sure. In fact I'm wondering about her identity. Most of us assumed she'd be Han and Leias' daughter. But what if she's a Skywalker? The trailer starts with her and someone asking who she is. Her clothes are very Skywalker like in color and style. Both Anakin and Luke started out in light colored clothes at the start of their journeys. If she is a Skywalker she doesn't seem to know anything about her roots as Han has to explain a key factor. If that's true then she can't know Luke which would mean he'd have to give up a kid too.
Finn is curious since he seems to be a Stormtrooper and has a lightsaber. I'd think it could be a misled if not for the poster. Much like Rey his last name isn't mentioned which means we know someone from his family from past movies. I even speculated him being Lukes' son at one point. I heard a theory of him being Hans' son/grandson from his first supposed marriage that's mentioned in the comics. If that was true then where would he get his abilities from?
Ren is devoted to finishing what Vader started. Why? Unless he knew him or is related to him it doesn't make much sense. Being a pupil doesn't fit since Vader wanted Luke to fill that role. What did Vader do that needs finishing? He was under the Emperors' thumb since his turn to the dark side. Vader did things for himself but nothing that's in current canon was notable except trying to bring Luke to his side. Maybe the reason for his turn? Learning how to prevent death? He seems to be using a previously unsee Sith technique on someone.
To everyone moaning that Leia looks old get over it so does Han. It was still good to see her with him and hear their love theme in the trailer.
Han takes a surprising role in this and one that has delicious irony. It seems that the Jedi, the Sith and the force are considered myths. This is depressing since it implies Luke didn't bring back the Jedi and it doesn't sound like he trained any. I know I'll be ticked if Leia STILL doesn't know how to use her abilities. Anyway back to Han, remember in ANH when he scoffed at Lukes' training and didn't believe in the force? He learns to respect Luke and by proxy the force although not much is made out of this. Just him basically accepting it. Now he's the guy that tells others that yes, the force is real. That brings us full circle. In an odd way the trailer seems to imply Han is the Obi-Wan of the movie that's guiding the others. Even his scene with Finn and Rey reminded me of AOTC Obi-Wan. Can you guess why? I love it I just hope he doesn't meet the same fate.
No Luke yet which is building up anticipation. While I'm not super hyped I like what I've seen.