Not much solid info here, but some of it was kind of interesting;
http://www.starwarsnewsnet.com/2016/01/the-rumored-cast-of-star-wars-episode-viii.html

Apart from Trevorrow confirming that both Mark Hamill and Carrie Fisher will be in ep. IX, plus the already discussed re-appearance of Harrison Ford, it seems that Max Von Sydow might return as well.

People have already speculated how Han may make an appearance in a flash-back, a hologram, or even as a Force ghost (the last one I personally don’t buy), but I guess it’s not out of the question that Lor San Tekka might appear as a ghost, being that he clearly has some relationship with the Jedi and the Force, and that he was referred to as the “vicar” early on. Or both Han and Tekka might be showed into another Force-flash-back scene alongside a bunch of other stuff.