In between all the films, Star Wars has lived on and continued to grow thanks to the Expanded Universe, a sprawling series of novels chronicling everything from the further adventures of Luke to the farthest corners of the galaxy. When Disney bought Lucasfilm and announced that it was making a new trilogy, fans of the EU were left disappointed when it was de-canonised. You could see the logic in wanting a fresh start and the chance to take the new stuff in whatever direction they wanted, but many were unhappy at so much material being wiped out like Alderaan. There are still hopes that parts of the EU - or Legends, as it's now called - will be used, and indeed if Abrams or anyone else wanted to dip into it and take stuff they'd be well within their rights. However, anyone expecting Rey and Kylo Ren to actually be Jaina and Jacen Solo is going to be rather disappointed, while Boba Fett is almost certainly still dead.