Card has been working for years, pretty much since the novel was written, to make sure that if an Ender's Game film is done, it will be done right. He has gone over all the contracts that have been brought to him with fine tooth-combs and discarded any that weren't completely acceptable, he has come up with several screenplays for it himself and is working on another last I checked... In short, the author himself is completely dedicated to a GOOD Ender's Game movie, and is micromanaging to make sure that this happens.
Which, of course, doesn't mean it will wind up actually being good, but at least it inspires some confidence.
I don't know, if their original creators had been consulted more, League of Extraordinary Gentlemen might have been better, but V for Vendetta would have sucked, so it's hard to tell.
I was about to cite the good adaptations of the Harry Potter books to movies, then I realized that if you start with pap books, it's not hard to wind up with a movie that's at least as good as the books.