I think there's a good chance that SW will end up like superhero movies in that they will mostly do their own thing but occasionally borrow from popular material (novels, comics, maybe). That's not necessarily a bad thing.
What I think a lot of fans need to realise is that not every novel they ever read will be incorporated into the movie. Just as all the Spider-Man stories from his 60 + years in the comics will never make it to the movies. But that does not mean, of course that those comic stories "never happened". Of course they did, and you can enjoy them again and again, and you can also enjoy a good Spider-Man movie at the same time.
I use this comparison because it seems a lot of SW fans are worried that a book they really like will suddenly "not count" or something because the new movie will contradict it. It most likely will. But this universe is going to grow with the Disney buy. Superhero universes have different continuities (comics, movies, cartoons, etc) Until now SW has had ONE continuity but frankly, I think those days are numbered. On the bright side, a good superhero comic is still a good superhero comic. A good superhero movie is still a good supehero movie. Even if they don't mesh with eachother. Star Wars can be the same way.