Everybody remembers the wonderful final scene from the famous movie, but only a few people know its secret. Actually, the animation of the dance was borrowed from other renowned Disney couple. The dance between Belle and her Prince in the finale is actually reused animation of the dance between Princess Aurora and Prince Phillip in Sleeping Beauty. The original Sleeping Beauty couple had been drawn over to become the new Beauty and the Beast couple, and this was done because they were running out of time during the production of the movie

More Info: en.wikipedia.org