Whether or not Lex Luthor will be in Man of Steel hasn't really been talked about. In fact, I think a lot of us have just assumed that he's not going to be in it, but that might not actually be the case. In a recent interview with I Am Rogue screenwriter David Goyer was asked about the decision to leave Lex out of this latest Superman film. Instead of explaining why the villain wasn't included though, Goyer threw a curveball and said...
I don’t think anyone has [ever] confirmed that we haven’t included him.
Whaaa? Now here's the kicker, the person doing the interview didn't even ask a follow-up question! How can you not ask a follow-up question to that comment?! That was a golden opportunity to really try and dig into the role Lex might be playing in this movie, and instead the journalist lets Goyer off the hook.
I looked up Man of Steel's IMDB page and there's no actor being credited as Lex so if he is included they are really trying to hide it, or he's going to be part of a post-credit end scene. Or maybe he's there in spirit, in the background brewing throughout the story, with people talking about him. We'll eventually find out when the movie is released on June 14th!
If Luthor is involved that would be cool, I just don't think he'll have a main part to play in this story.