Dawson Casting: Inverted. Aurora is 15/16, while Elle Fanning was 14 during filming. Compare that to the original film, where Aurora looked like she was in her 20s and was voiced by the just-under-30 Mary Costa.
In the German dub, Diaval is voiced by Timmo Niesner, who commonly voices Elijah Wood characters (most famously Frodo).
The Other Marty: India Eisley (Eve from Underworld: Awakening) was originally cast as Young Maleficent, but she was replaced with Ella Purnell after Disney executives expressed displeasure with her performance.
Real-Life Relative: The girl who plays the young Aurora is played by Jolie's daughter. This had to be invoked since she was the only child that didn't get scared when she saw Angelina in costume.
Two of her other children are nobles in the Christening scene at the beginning.
Recycled Script: A lot of the dialogue in the Christening scene was actually lifted from the animated film that Disney made years ago, with some of it being repurposed and additional dialogue inserted. The description of what happens afterwards also has this.
Sleeper Hit: The film was expected to be a Box Office Bomb for Disney and despite mixed reviews, it wound being a financial hit, grossing over 700 million worldwide.
In fact, it's domestically outgrossed films such as Godzilla, Amazing Spiderman 2, X-Men: Days of Future Past, 22 Jump Street, and Teenage Mutant Ninja Turtles. This is in part due to a weak summer box office.
The original script had King Stefan as a much darker character, being the half-fairy bastard son of the King rather than just a farmboy, who never actually loved Maleficent at all, and who murders his father to take the throne rather win it from the already-dying King as in the finished film.
It also included an actual Queen of the Fairies, Ulla, Maleficent's aunt, who cursed her with her horns to mark that she was a nuisance (her big wings were often disruptive), and Maleficent's father was also a minor character. Miranda Richardson and Peter Capaldi were cast as these characters, respectively. These scenes were filmed but they were sadly cut.
Maleficent was also supposed to be far colder to Aurora initially; instead of sending Diaval to care for her as a baby, she was to, effectively, leave her to die, and Diaval would end up secretly looking out for Aurora while bringing Maleficent around.