There aren't levels of canon. It's canon, or it's not canon. Now, I don't really care if the EU books are canon or not. I do admit that without those novels and comics, we wouldn't know the names of so many characters. I've read many of the comics, but I don't consider them canon. I don't think about what happened in them when I watch the movies. They're just fun reads. Let's step out of SW for a second, and consider others. All the Star Trek novels, for example (because I have such an extensive collection). There are some really great stories, but they're not going to change what happens in the show. They are stories that happen in the Star Trek universe, maybe even with familiar characters, but to me, they're just professional fan-fiction.

That's the same way I see the EU. Stories from the Star Wars universe. Professional Fan-Fiction. Next, you're going to tell me that what happens in Star Wars: Galaxies is canon.