There is a prequel book, a whole toy line (already, yes - I think that's why they're making this movie actually), and accessories popping up all over the place.
Here's the main trailer (there are also character trailers which you can watch HERE):
I'm... not quite on board with this whole thing.
Ever After High already does it better. Way better.
My biggest problem with it, is that any substance in any of these stories, fairy tale, mythic or otherwise, really appears to have been watered down very significantly and left without much of a leg to stand on, Instead of being a fun fantasy with substantial roots, it's turned into dismissible fantasy fluff (with what-the-heck costumes). The character promos at least talk about the 'origin stories' of their 'parents', and it does look like the cast had fun at least, but these villain-kids don't hold a candle to what the Ever After High characters (who are also descendants of fairy tale characters) have to deal with and make decisions about.
If you'd like to read up on it though, here's a little about the book, available for pre-order:
Description:Evil tree. Bad Apple?
Twenty years ago, all the evil villains were banished from the kingdom of Auradon to the Isle of the Lost--a dark and dreary place protected by a force field that makes it impossible for them to leave. Stripped of their magical powers, the villains now live in total isolation, forgotten by the world.
Mal learns from her mother, Maleficent, that the key to true darkness, the Dragon's Eye, is located inside her scepter in the forbidden fortress on the far side of the island. The eye is cursed, and whoever retrieves it will be knocked into a deep sleep for a thousand years. But Mal has a plan to capture it. She'll just need a little help from her "friends." In their quest for the Dragon's Eye, these four kids begin to realize that just because you come from an evil family tree, being good ain't so bad.