Let's not forget A Very Supernatural Christmas, Jump the Shark, and Mannequin 3: The Reckoning. There are so many episode titles that are a play on words for real movies and TV shows. Yet one more reason I love this show.
To put it bluntly, those three shows are owned by Disney- the others are owned by different studios. Also, Supernatural is about supernatural stuff, which doesn't fly with Dr. Who or Sherlock. It will never happen...get over it and get on with writing more erotic Sam/Rory slash fiction.