Although its gone virtually unreported, I believe that Lucasfilm recieved the full rights to Star Wars in exchange for Fox getting full distribution rights for the prequels. Very smart--Lucas finally bought the only film that Fox owned because Fox would do anything to get the next Star Wars trilogy (indeed, it netted them som $1 billion+). Thats why the older video boxes say ESB and ROTJ are copyright Lucasfilm and Star Wars copyright Fox but starting with the SE I believe everything belongs to Lucasfilm.