Creator Cameo: The director's blood is used in the opening scene. He didn't feel the fake blood looked realistic enough, so he pricked his own finger to get the effect he wanted.
Deleted Scene: A few are included in the extended DVD release, which also features quite a few longer cuts of scenes. Deleted scenes include Snow White and the Huntsman making their way through the forest, and perhaps the most significant, a conversation between William and the Huntsman about the "light" inside of Snow White.
Star-Derailing Role: The fallout from Kristen Stewart and Rupert Sanders' affair got them kicked off the franchise and made them toxic for bigger-budget projects. Future films in this franchise will now focus on Chris Hemsworth and the Huntsman character. Given Stewart's dislike of her fame from Twilight, it's likely this is intentional as she's focused mostly on smaller projects since.
The Huntsman was scripted to be an older character - with actors such as Viggo Mortensen, Tom Hardy, Michael Fassbender and Hugh Jackman being considered. Likewise the kiss that wakes up Snow White was planned to be a symbol of fatherly love, meaning this movie nearly got there before Frozen.
Winona Ryder was the first choice for Ravenna, but she declined. Angelina Jolie was also offered the role, which would have made Maleficent hilarious.
The poisoned apple scene followed the original fairy tale in the first draft. However the director felt that was too standard, and instead came up with Ravenna disguising herself as William instead.