Only movies and The Clone Wars are canon.
Lucasfilm has revealed that all Star Wars books, comic books, video games and any other forms of media interpretation of the sci-fi franchise are non-canonical to the story, and only the six movies released so far and the Clone Wars TV show are canon.
This means that games which were considered important to the Star Wars mythos previously, such as Knights of the Old Republic and The Force Unleashed, are now actually non-canonical. All expanded universe (EU) iterations are non-canon.
“While Lucasfilm always strived to keep the stories created for the expanded universe consistent with our film and television content as well as internally consistent, Lucas always made it clear that he was not beholden to the EU,” an official blog post said. “He set the films he created as the canon.
“This includes the six Star Wars episodes, and the many hours of content he developed and produced in The Clone Wars. These stories are the immovable objects of Star Wars history, the characters and events to which all other tales must align.”
“Now, with an exciting future filled with new cinematic instalments of Star Wars, all aspects of Star Wars storytelling moving forward will be connected,” the blog continued. “Under Lucasfilm President Kathleen Kennedy’s direction, the company for the first time ever has formed a story group to oversee and coordinate all Star Wars creative development.”
There’s much more talk on the upcoming Star Wars films- not just the main three episodes to be directed by J.J. Abrams, but other possible films as well, in the blog post, so those who’re interested should take a look through the link above.