Very evocative title. I really like it.
It's interesting, because there was a line in the opening scrawl of Episode VII that said something like, "Luke Skywalker, the last Jedi."
I'm wondering if Rey has any interest in becoming a Jedi at all. I think she was fine with helping the Resistance and delivering the Lightsaber to Luke Skywalker, but I never got the impression that she wanted to pursue the life of a Jedi. I don't think it necessarily means that Luke is going to die either. Perhaps it's indicating that at the end of the film, Rey is going to reject the path of the Jedi, and carving out her own destiny, leaving Luke as the last Jedi. The ending of the movie would look grim, with Luke thinking that the Jedi are truly gone, as he is the last, and his students, Rey and Ben, have no interest in re-establishing the Jedi Order. The First Order could be looking primed for victory, and that would lead us into Episode IX.
In either case, I'm excited to have a title, and December can't get here fast enough!