Can't imagine we'll see much of Leia, but it is good to know that we will see her some and hopefully get a proper send off, without it being too overblown or cheesy.
I think we all assume we'll see Luke as a Force ghost. I think that I hope they leave him in sort of a "mentor" role for Rey, an inspiration to the Rebellion, and maybe he sort of haunts Kylo. Don't think I want to see him somehow be the hero again, I think it's time to let the new generation shine. I keep having this vision of Luke levitating way up in the sky with white eyeballs shooting lightning out of his fingers and it scares the shit out of me. I don't want a video game. We already have those.
Looking forward to seeing Lando, I think it's a mistake that they didn't bring him in earlier, let him and Han/Chewie have at least a moment in TFA, but better late than never, I guess.
The new cast additions Naomi Ackie, Richard E. Grant, and Keri Russell, all intriguing. I'm sure we'll learn more about their roles as time goes on.
Also be interesting to see what JJ does with Rose. Does he like the character? Will he keep her in the forefront? Or is he gonna tuck her away like Rian Johnson did with Maz (and Snap) and like George Lucas was pressured into doing with Jar Jar hahaha.
Do I have confidence in JJ's ability to close out not only this trilogy, but the entirety of the Skywalker saga fittingly? No. No I absolutely do not. But I'm hoping for the best. I hope he's putting that first, far ahead of the apparent behind-the-scenes tug-o-war that many believe to be going on.