@Jak: I kind of want Vader's force ghost to show up, and I also want him to tell Kylo that he was wrong all along about the dark side and how he was just being used by Palpatine. It'd be something to drive Kylo into wanting to take Snoke out of the picture (if Snoke is controlling Ren, like Han claimed). But not only that, but if Ren wants to be more powerful than Vader then he'd have to become the master himself. I think he'd only take from the "force ghost conversation" the idea that he has to be the one completely in charge and pulling the strings, so it'd set up some confrontation leading into the events of Episode 9.