I dunno......if he's stuck in the Phantom Zone....wouldn't he be left sort of like in a suspended animated state? He wouldn't really age at all.......
Or, hell....they could go with what Smallville did and have Zod inhabit the body of a human being, sort of like a host.
Miller has that cold and very calculating look.....he CAN be creepy too....and think about it: He might make an awesome villian VERSUS Routh.
Obviously, he'd have to follow Routh and hit the weight room.
But, hey big ups to the comic book world.....he was asked about a character from literature and went with Zod. Nice. Ya know he's gotta be a Superman fan for sure.