Cannon = Goes boom and shoots projectiles.
Canon = A general law, rule, principle, or criterion by which something is judged.
According to Wiki...
The official Star Wars canon consists of the six released Star Wars theatrical feature films, the Star Wars animated film and television series The Clone Wars and Star Wars Rebels, and every other material released after April 25, 2014, unless otherwise stated. The upcoming feature film Star Wars: The Force Awakens (along with the untitled Episode VIII and Episode IX) will also be a part of the official canon.
On April 25, 2014, Lucasfilm officially revised and solidified the canon, stating that all previously released Expanded Universe works would be re-branded under the new Star Wars Legends banner, in order to ensure a flowing timeline with the release of the Star Wars sequel trilogy. They also announced that future Star Wars stories will be considered on equal canon level with the films, with guidance coming from the Star Wars story group.
So this means that all those story arcs I loved starting with the Zahn's [/i]Heir to the Empire series, then the Rogue Squadron books and into the New Jedi Order books are now non-canonical and are supplanted by Force Awakens.
I'm actually okay with this. I love what Abrams did with Star Trek and am happier with the reboot there than I am with TOS/TNG/DS9/STV. As others have said, I'm really pleased that Lucas' hands are out of the writing mix. Kasdan is a big time upgrade.
I wait with baited breath.
-- Pat
PS - Luke as Sith Lord. Book it.