I hear that the star of the new version of the cult classic Doctor Who, actor Christopher Eccleston, has already quit, stating that he does not want to become "typecast".
Dream on, Chris.
Right this moment, there are actors with long careers, who are known only for their appearance in an episode of Star Trek, forty-umph years ago. They have fan clubs based on their character, entire fan clubs.
Sorry, Chris. You've been a Doctor Who. Forty years from now, you'll be "That guy who played The Doctor back in 2005, Oh, and he did some movies, too."
But look on the bright side - you could have been a Star Fleet Captain.