"Obviously, in many places those films contradicted what had happened in the comics. Which ones are more important? The films, of course. However Lucasfilm recognizes the creativity and diversity within the Marvel comics and feels there is a place for non-continuity events...Elements from the Marvel comics that don't tread upon that which has been established in the films, novels, comics, et cetera, are being integrated into the official star wars canon because we like them, they're cool, the aliens will be fun to use in the RPG..."
They've specifically told me, in regards to the Marvel stories, that events that can be fit into continuity are continutiy. Things that don't fit are apocraphal. However, given that such pronouncements tend to change depending on when they're made and who makes them, who can say? Regarding the Mandalorians, I was happy to try to find a place for them in the Clone Wars comics . . . until that didn't seem enough for certain parties. After all of the begging, demanding, screaming, and shouting that's has transpired, I'm no longer inclined to make any mention of the the Mandalorians. Certainly, the way it supposedly happens in the Marvel continuity (the Mandalorians fought on the side of the Emperor during the Clone Wars, with Leia being specifically mentioned as an enemy of the Empire) could not have happened. There was no "Emperor" during the Clone Wars, and Leia wasn't even born yet
a : a regulation or dogma decreed by a church council b : a provision of canon law 3 [Middle English, from Late Latin, from Latin, standard] a : an authoritative list of books accepted as Holy Scripture b : the authentic works of a writer c : a sanctioned or accepted group or body of related works <the canon of great literature> 4 a : an accepted principle or rule b : a criterion or standard of judgment c : a body of principles, rules, standards, or norms
Well, in real life, Canon is not generally something defined by the person/s who write's something, but generally by a council of peers,
Let's see, Palpatine claims that the republic had only been around for just over 1000 years. The EU overides it and made the republic last 25,000 years, choosing to follow what Obi-Wan said in ANH, in order to protect the EU's history.
Dooku's ship is called the Solar Sailer, but in the EU there is nothing solar about it, it uses mysterious gree energy waves in order to fly.
There is sound in space in the movies, but in the EU there is no sound in space, except in few circumstances involving atmosphere pockets and other phenomena that the EU chose to explain sound occuring in space...