SM has said that she was virtually a producer on Eclipse, so I don't know if it's a case of her coming in at the last minute. She has certainly been involved all the way along, and from what I have gathered in interviews her involvement has only increased.Regarding SM as a producer, I think most fans are in agreement that this wasn't the best move. It would be different if the scripts had been more faithful to the novels in their depictions of certain things. But, they weren't. So, especially for SM to swing in and try to drag the films kicking and screaming back on to that track is kind of like using scotch tape to fix a hole in the boat.
I must confess I wasn't pleased with Eclipse, but I felt that the other two movies were good adaptations of the books, considering the difficulties (as has already been mentioned) in turning a book into a movie. It's not an easy task. I was worried about Eclipse from the outset, as I felt that David Slade was an unsuitable selection for director. Once I saw the finished product I felt I was justified in my worry. However, I think Bill Condon has a bit more of an understanding than Slade had. The trailer is suggesting that, anyway. So I am growing in confidence that BD will be a good movie.