So what's the discussion on Luke's line in the trailer? Has that already played itself out?
Honestly I'm kind of afraid of what they might do with it. In an interview Hamill said he had some fundamental disagreements with what TLJ is going to do with Luke.
Personally, I don't agree with the comments I've heard on light/dark side balance and crap. I know people don't like going along with Lucas's intentions anymore, but the light side of the Force pretty much IS supposed to be the balance. ROTS presented some interesting contrasts between the Jedi and Sith, but the flaws of the Jedi were really just about the organization, not the light side of the Force itself. Get that grey Jedi bullshit outta here.
The biggest questions obviously have to do with what happened when Luke tried to restore the Jedi. He has no image of what the original order was like, only what Yoda and Obi-Wan taught him. It makes perfect since for him to realize that the new Jedi can't be the old Jedi, but I find it hard for him to believe the whole organization itself must go. Maybe the revelation is that the light side of the Force needs to be reinterpreted and represented by something else. Even the Knights of Ren don't consider themselves Sith. They're just a new force that has reinterpreted the dark side in their own way.
Oh, and I still really hope Rey and Snoke don't have any connections to OT characters.