Now that we've all had the weekend to absorb the new movie poster and trailer for The Last Jedi, it is time to share my thoughts.
First let me say that this is a well-crafted trailer. Though I was of course excited to see it, a part of me almost didn't want to watch it because I didn't want the secrecy to end. I need not have feared: there are no spoilers in the trailer. Just enough to let us see the movie without seeing anything that we shouldn't yet.
But what did we see and what did I think of it?
Rey, presumably training with Luke. Exciting, but nothing we weren't expecting.
Leia, in a shot that makes her look very much like Vader. Hinting at something? I can't see darkness coming from Leia, but maybe the shot hints at the legacy of darkness that Leia carries. Or possibly we do learn something that Leia did, perhaps in raising Kylo that helped give him an excuse to turn away. This could simply be the fact that, as revealed in Bloodline, Ben was already an adult when he found out that Darth Vader was his grandfather--which must understandably have made him pretty angry at his mother and his uncle, that they wouldn't have told him this before. Anyway.
Speaking of Kylo Ren. What's that we saw? His mask all broken up? What does that mean? Does his mask literally break, or are we seeing it in a vision, perhaps one that Rey has? Either way, for his mask to break has a symbolic meaning that his dark exterior he has cultivated for himself is breaking. Notice, of course, that we mostly saw Rey in this trailer. Presumably this is because showing Rey on the island "gives less away" than showing Kylo in probably most of his scenes. When we do see him, he isn't wearing his mask--and I'm expecting that he probably won't wear it much in this movie, for whatever reasons.
Finn and Poe are back. Cool. Again, nothing we didn't already know.
Luke speaks. It's funny, after leaving him with no words in TFA, he gets to narrate this trailer. His words are intended to sound like words he says to Rey on the island when he is training or considering training her. But they could be from anywhere in the film, or possibly not even be in the film (after all, he had lines in the TFA trailer that weren't in the movie). So bear that in mind.
When he says that it's time for the Jedi to end, I believe that he is primarily speaking out of guilt or regret for the past. He feels like he could have done better. That's all there is to that. As far as the movie title goes, I'm in favor of the threefold meaning: after all, many of the other titles have multiple meanings, as well. The last Jedi as in Luke is literally the last Jedi left, and it is him that Rey goes to meet and possibly train with in this movie. The last Jedi as in the last generation of Jedi, the trio of Luke and the two people he has trained, Ben and Rey. Perhaps we will learn more about Ben's past and Rey's past that will lend to this trio image. The trio image is also displayed in the movie poster, where Rey acts as the light and the agency and Luke and Kylo are the darkness and the power--and she has influence over them because she is the one holding the lightsaber and they are the ones that spring from the image of the saber. (Interestingly, the red/darkness does spring from the saber, implying that power can all too easily lead to darkness.) And the last interpretation of the last Jedi is, of course, that the Jedi Order as it is will officially come to an end. This is easy to see since the flaws of the Jedi are constantly visible, especially if you include the prequel trilogy. It makes sense that Luke, possibly with Rey's help or insistence, decides that making changes to the system is what will help them move forward into a new generation.
Overall prediction? This movie will see a change in characters' resolutions. Rey, Luke, Finn, Leia, and Kylo will all either make a new resolution or further resolve a current one. This is the start of a new day, and it will probably be a rocky start if it's anything like how fiction (and life, too, I guess) usually is.
The Last Jedi. Let's just relish the ominous sound of that phrase for the next eight months.