Here are my picks, they are based on picking people who are well established mega stars, who are still on the 'cool' radar. I think they are looking for BIG NAMES... if they are not so hot anymore they may not be considered; E.G. Timothy Olyphant is not that huge a star to be Lex (in Zack's brain) and Kevin Costner is "bigger" than Quaid.
Lex Luthor - Adrien Brody, Daniel Day Lewis, or True Blood's Alexander Skarsgard
Perry White - Denzel Washington, Jeff Bridges, or William Hurt
Jor El - Liam Neeson (there is no other choice, no matter how overused he is, he was born to play this role.)

Jimmy Olsen - Anton Yelchin
Lois Lane - Gemma Arterton

Zod - Viggo Mortensen (not to hard to predict this one, but I'd rather not see Zod yet)
Brainiac- Zachary Quinto