There's an Ender's Game movie in the works... http://www.imdb.com/title/tt1731141/ and http://endersgamemovie.blogspot.com/
What little I've seen/heard about it is promising.
But to make a movie, or even a limited series, of any of the Callahan stories? I don't think they'd translate well. I think too much works on the puns, on the unexpected verbal twists (like the twist in who is a time traveler in one of the earliest stories... which I won't say more about to avoid ruining the fun! Go READ THEM FOR YOURSELF!)
What little I've seen/heard about it is promising.
But to make a movie, or even a limited series, of any of the Callahan stories? I don't think they'd translate well. I think too much works on the puns, on the unexpected verbal twists (like the twist in who is a time traveler in one of the earliest stories... which I won't say more about to avoid ruining the fun! Go READ THEM FOR YOURSELF!)