One return by an old companion that may have been considered was a cameo by Ian Chesterton (William Russell) for the 50th anniversary special. In the end, Chesterton didn't make a personal appearance but he was listed as a school governor on the sign for Coal Hill School and shown in a photo on a wall in the Black Archive. Ian has also been mentioned in passing in the Sarah Jane Adventures in which it is claimed that he and Barbara are now immortal. As would be expected, Ian has also appeared in the spin off comic strip in Doctor Who Magazine. Some sort of actual in-the-flesh return for Ian would be marvellous. The justification? It would make so many people so very happy. But the producers of Doctor Who need to hurry up. Without being morbid, it's enough to note that the chance of William Russell reprising his role won't last forever.