Ok , with all the news and rumors swirling around lately I'll give this a go. I'll give a few choices for each with the consideration in mind that Snyder and Nolan might want to use a few actors they've worked w/before.....
Superman/Clark Kent: Henry Cavill is my no. 1 choice right now, but I also really like the idea of John Krasinski(who I still wish would've gotten Captain America), and while I'm not familiar w/ Armie Hammer's work, he certainly has a good look for the role.
Lois Lane: I'll throw in Malin Akerman for a Snyder-based pick, though I'd prefer Rashida Jones(my no 1), Rachel McAdams or Emily Deschanel.
Lex Luthor: Jon Hamm would be fantastic for this role (he'd make a great Supes too, but he's just too old now)....my only concern is that he might not wish to shave his head due to "Mad Men", which being a period piece requires a certain look of him. I also think he looks a bit like an older Michael Rosenbaum (HANDS DOWN the best live-action Lex to date). I could also really see Jason Isaacs, or for a younger choice Cillian Murphy.
Brainiac: Two words...TOM...HARDY. Best choice for this role. I'm actually surprised so many people here are casting him for Lex rather than Brainiac. Jackie Earle Haley might make an interesting choice too.
Zod: Gerard Butler. If the rumors of Zod as the villain are true, this seems like a lock.
Perry White: Jon Voight or Tom Wilkinson
Jimmy Olsen: Anton Yelchin or Jamie Bell
Pa Kent: Jeff Bridges
Ma Kent: Susan Sarandon
Jor-El: Jim Caviezel or Eric Bana
Lara: Lena Headey