Fisher, Hamill, And Ford Guaranteed To Return Since The Beginning

While Carrie Fisher and Mark Hamill's return for Episode VII has been called 'the worst kept secret in Hollywood', Harrison Ford's return to Han Solo hasn't seemed so definite, especially, given his distain for the character over the years. Their return has never actually been in question, as Lucas met with them prior to the Disney sale to guarantee their participation. Fans of the original cast should also expect more than just cameos, as, according to sources, Hamill and Fisher will boast "strong supporting parts", with, Ford joining three of the young stars as one of the leads in the story.
(Source: InsideMovies.EW