Despite Zack Snyder's insistence that /no-general-zod-for-superman/General Zod will not be the villain in his upcoming Superman reboot, the director and producer Christopher Nolan are currently eyeing Viggo Mortensen for that exact role.
Viggo Mortensen is still in /kristen-stewart-circling-viggo-mortensen-joins-snow-white-and-the-huntsman/negotiations to play the Huntsman in Universal Pictures fairytale retelling Snow White and the Huntsman. If he does not close the deal, he will move directly into Superman. If he does play the Huntsman, the hope is that he will be able to work out his schedule with Universal Pictures and Warner Bros. so that he can do both movies.
At this time, sources close to the actor claim that talks have not commenced and that when it comes to portraying General Zod, Viggo Mortensen is just a "person of interest". The same is true of Kevin Costner, who was recently /superman-gets-kevin-costner-as-jonathan-pa-kent/announced as Pa Kent. While other actors are being considered for both roles, Viggo Mortensen and Kevin Costner are at the top of a very short list.
Zack Snyder is also in the midst of casting Lois Lane and General Zod's right-hand woman /superman-brings-back-ursa-as-its-villain/Ursa, with Alice Eve, Diane Kruger and Rosamund Pike rumored to be up for that role.
Official casting announcements for Superman are expected soon.