If someone posted this earlier, pardon me. One confirmed returning cast member. ;)
http://starwarsblog.starwars.com/2013/11/19/r2-d2-is-in-star-wars-episode-7-and-hes-fan-made/
Nice to see some fans get a chance to become part of the production.
I'd still like to see Kenny Baker return for sentimental reasons. You'd think with modern tech they could make a Artoo he could "drive" with a tiny camera and LCD monitor. Those remote controlled Artoos run amok on the set sooner or later. ;)