Many websites are citing rumors that Emperor Palpy is coming back, likely in force ghost form. The idea is that he had a new apprentice before dying and he is the mastermind of the bad things to come in the new trilogy.
Pretty cool/interesting if true!
He said he'd love to make more Star Wars one day (expressed a wish for a Palpatine spin-off movie about the Empire years) and would of course reprise the role if asked, but he isn't in episode VII. He candidly explained that the Emperor is dead in that time frame, and though it's a universe with the possibility of "reincarnation" via cloning, holograms and ghosts and such, he's just not in the movie.