George has outlines, but they're still working on the story, so even though we know absolutely nothing about the new trilogy's plot, it's time to start the speculation. Even if it has nothing to do with the Skywalkers or their offspring, it's a good bet that the sequel trilogy (ST?) will at least have cameos from preexisting characters. In what capacity they should be used, or if they should be used at all, is up for debate - but who might they include?
*R2-D2 and C-3PO - Some people felt they were shoehorned into the PT, but I can't imagine films completely without them. Maybe it could be about their new owners? Anthony Daniels is always ready and willing to play C-3PO, too, though he may want to just do the voice by the time they go into production. They'd probably go with a mix of CGI and remote control for R2-D2, as they did on ROTS. Plus it's not like there's an aging factor to worry about with the droids.
*Jedi Spirits - It's not outside the realm of possibility to have Hayden as Anakin, Yoda, Liam as Qui-Gon, or even Ewan (who mentioned his interest on Twitter) as Obi-Wan appear to the Jedi as spirits, even briefly.
*Luke Skywalker - Mark Hamill also Tweeted his interest, and he mentioned at CV how George had asked him (I presumed it was a long time ago, but it could have been more recently) to appear in the sequel(s) and pass the torch to the new generation of Jedi. The trilogy doesn't have to be about him or his family, but I would like for him to make an appearance as a Jedi Master.
*Leia Organa - With the established EU likely going out the window, the last we saw Leia, she had learned that she came from a family of Jedi but was hesitant about acknowledging her powers. Could she be on a reformed Jedi Council with Luke?
*Han Solo - Harrison Ford has said he has no intent to return to play Han Solo, not finding him as interesting as Indiana Jones, but that was before the new movies were announced. With Episode VII coming seven years after Crystal Skull, I doubt he'd have an action-related role, but he could possibly appear.
*Lando Calrissian - It seems they haven't given him a ton to do in the EU, but Billy Dee has done the voice for Robot Chicken and Detours, so it's possible he could appear in the actual films.
*Chewbacca - Though he died in the EU, Chewie has turned up again in ROTS and TCW, with involvement from Peter Mayhew on both.
*Clone Troopers/Stormtroopers - It could be interesting to see Temuera Morrison as an aged clone to see how they have reintegrated into society in peacetime, unless all the clones died by ROTJ.
*Jar Jar Binks - I somehow doubt this.
*Darth Maul - Even though he's alive on TCW, I assume he'll be killed by the end of the series, and I doubt they'll reintroduce him to the films.
*Rebel Leaders - Wedge Antilles, Mon Mothma, and Admiral Ackbar could be involved in leading the new Republic. Hell, even Wicket could show up and blink for a few minutes.
*Bounty Hunters - Darth Maul survived getting cut in half, so Boba Fett could surely survive the Sarlacc. We also don't know the fates of Cad Bane, Aurra Sing, or Asajj Ventress, so any of them (or any of the hunters from ESB) could appear as well.
*Ahsoka Tano - Who knows? They might go nuts and have her survive the Clone Wars, only to reappear decades later to help the Jedi.