Variety reports, now that Asa Butterfield (Hugo) is officially cast as Ender, the casting team has started looking at the other roles that need to be filled. The adult lead of the film is Colonel Hyrum Graff, among the possible actors to play the part, Viggo Mortensen was previously being looked at, now the talk is all about Harrison Ford.
While no word has been heard from Ford or his people, the sci-fi fan favorite seems like a good fit for the role. Butterfield is the only official cast member so far.
The Orson Scott Card adaptation is being produced by OddLot Entertainment, and Roberto Orci and Alex Kurtzman via their K/O Paper Products. Card is also signed on to produce with Lynn Hendee and Robert Chartoff.