I think it's inevitable that the sheer existance of the EU will do that. The more you expand and fill in the blanks, the less there is to imagine. I think, in some alternate universe, it would be awesome if there was no EU, no games, books, comics, no nothing, just the films--and what kind of crazy discussions we would be having. Everyone would have their own take on what the SW universe was like. For those who remember before the prequels: what the heck was the Clone Wars? No one knew, but we all kind of had our own version of it. I miss that. But, on the other hand if there was no EU I wouldn't have stuff like Rebel Assault II or Heir to the Empire or the SW Radio Drama, so it's a mixed bag.