Rumors are floating around right now but I would say take them with a grain of salt. With that being said, the latest rumor for whom will play the role of Lex Luthor is leaning towards Terry O’Quinn (LOST). I thought that Bryan Cranston was a solid choice and from studio talk, it seemed like he had sealed the deal. I hadn’t thought of Terry O’Quinn playing the role but I’m not opposed to it either with myself being a HUGE fan of the show LOST.
According to Superman SuperSite, their sources close to the production are indicating that Terry O’Quinn is in the running to play Lex Luthor in Batman Vs. Superman. Of course, Terry O’Quinn is best known for playing John Locke on LOST, and he has long been considered a fan favorite to play Lex Luthor.
But, to reiterate the point of taking things with a grain of salt, these rumors could be nothing more than generated fan buzz. Remember how many rumors we had for Batman? Karl Urban, Ryan Gosling, and Jon Hamm were all rumored to be in the running for the part and then out of nowhere we get Ben Affleck. The studios should probably sign someone soon before the rumors get too carried away and there’s another huge uproar because they didn’t pick who “we” wanted.
Since neither of these actors are confirmed choices, I’m going to start the rumor that Vin Diesel is in the running to play Lex Luthor. At least he looks good with a shaved head :P

I got the perfect actor for who should play lex luthor in the batman vs.superman movie and its patrick stewert
What if Tim Roth were Lex Luthor? He has great talent as an actor. He could portray Lex as a calculated, and cruel – yet charming villain.
“He can’t play an evil character” – err, watch Lost….. Terry O’Quinn can be extremely sinister, in a disguised and disturbing way
Terry O’Quinn would be a terrible choice for Lex. Not taking anything away from him as an actor, but that is not the role for him. He can’t play an evil character. He’s more of a wise guidance type. For those who have seen the darker parts of Breaking Bad, they KNOW Bryan Cranston is the optimal choice.