IM CALLING that the following scene will happen:
Just as the movie is about to finish Han, Leia and Chewie (and maybe somebody else) will be trapped into a life/dead situation with one of the main bad guys threatening to kill them, they have no way out, this is the end for them and suddenly after 2 hours of movie and many small teasers about Luke shown throughout the movie, Luke Skywalker is going to show up at the scene, the entire audience is going to think "finally where the hell have you been Luke? we've been waiting for you to save the day" Luke is going to start his lightsaber, he is going to pass the bad guy, stand in front of Han, Leia and Chewie and he is going to push that lightsaber with all his anger on the body of Han Solo, Han and Luke will look at each other as we see Han Solo struggling for his last breaths asking himself "why why" and Luke is going to let him die and fall with absolutely no remorse.
With that scene JJ Abrams will create the BIGGEST evil character in all Star Wars movies, NOBODY on eath, hell nobody in the Galaxy is going to forgive Luke for betraying and killing Han fucking Solo. This is going to set the tone and the story for the entire new trilogy. As bad-ass as Kylo Ren looks, they need a BIGGER and more powerful bad guy, who better than the new master of the force, the last Jedi alive, Luke Skywalker, NOW... shit we have story for a brand new trilogy
IM CALLING IT now, maybe not exactly as described on every detail but this scene will happen in one way or another.