So much of Ender's Game is about the psychology and sociology of Battle School that I think my main concern is that that's also an important part of the movie, that it's just not another VFX-driven alien invasion spectacle. You really can't make any judgments off the trailer alone, because obviously it's going to play up the pretty visuals, and I have nothing against them showing 'footage', as it were, from the first two Formic wars. And I have a lot more hope than I otherwise would if OSC hadn't been involved in the movie.
Also, where is Bean? I NEED ME SOME BEAN.