I agree that the Bean saga would probably make for better action movies post-Ender's Game. Plus, it would help explain the whole story in chronological order, which helps give some more background for Speaker. And I agree that Speaker has a whole different feel to it.
EG really personifies childhood in general to me in the sense that it's all about actions. Not a lot of us get the chance to stop and reflect on our actions when we're young, and neither does Ender, which is natural. EG is relatively fast paced story (my, how fast-paced childhood seems when you're done with it) and, like childhood, our character makes choices in that time that he only later fully understands. And Speaker has pretty much the opposite framework. By that time we know who our characters are, to me it's really about watching them struggle with their regrets, current and future decisions. Admittedly, it's harder to make an action movie about a plot line that puts more emphasis on a character's thoughts. But at that point, once the movie's come out. I think the audience will be clamoring for more Ender. It's hard to just stop caring about our favorite superhero/villian/xenocide, now isn't it?