Dismissing the novels as fanfic has eternally put Terra on my bad side, not that she's around much anyway.
A few years ago I did a report on the movies in an attempt to determine what made them enjoyable. Serious research, went in loving the trilogy, loving the novels, and liking Episode 1 (before Ep2). Came out hating all four films and realizing that Lucas simply got lucky with special effects geniouses for the initial success while its continuation is mostly caused by the genious of the writers that suceceeded him.
I'll skip over the fairly disturbing conclusions I reached and statements by Lucas himself that are truly abhorrid and cover some facts.
The Star Wars universe, as originally envisioned by Lucas, was nine movies long, covering Anakin Skywalker as a central figure, with 7-9 showing Luke eliminating his legacy. No matter how Lucas tries to spin those, he'll stomp the novels. Cannon or no, he sold the rights to those authors and if he starts contradicting it that much the fanbase is going to split even worse than it has. That's a really bad buisness decision; the early days of SW:G were plagued by book followers versus game followers versus movie followers with the game trying to reconcile them all and alienating everyone to some degree. The discussions died down quickly, but that's because the contradictions are, as yet, minor. Ep3 could botch any further attempts at in-continuity games. Going beyond 6 is asking for Lucas to shut down LucasArts. Not going to happen.
As for the backstory (1-3), Episode 1 not only damaged continuity within the movies themselves (read the Ep4 screenplay. Kenobi calls Artoo a modern R2 unit he didn't recall owning. While the latter is true, modern is certaintly wrong) but redefined the Jedi and Force with the midichlorian concept. I have *never* come across a serious Star Wars fan who doesn't scream in pain at that word.
Episode 2 was very hard on the books and none too kind on the movies, perpetuating the damage from Ep1 and seriously comprimising the laws of physics(Star Wars maintains a fairly decent adherence to scientific knowns) with Duuku's sail ship thing.
Episode 3 can do no better. Lucas got lucky with 4-6. He proved senile with 1 and arrogant with 2. The Dark Side has him, he's going for a target audiance of uneducated, unimaginative, slow, and frankly stupid majority. Also children who trump those requirements with innocence and a lack of understanding of how much potential the movies throw away.
Six inches of cute brooding war hero.