“Superman is like James Bond, and after a certain run you have to look at new actors.”
That quote, credited to an anonymous source, appears in The Hollywood Reporter’s initial story about Henry Cavill quitting the DC Extended universe. There is still no firm confirmation as to who will replace Henry Cavill as Superman in the DC Extended Universe (DCEU) and based on what we can gather from the THR’s story, WB currently has no solid plans for a new Superman movie going forward, so it’s doubtful the studio is in any hurry to recast the role.
Even when the recasting process does begin, tradition would suggest that WB will opt for a relative unknown over an established actor, so it’s difficult to predict who would even be in the running for such a role at this juncture. That being said, it’s hard not to speculate whenever an actor leaves a big role, so we have a few names in mind for who we’d cast as Superman if the superhero were being recast right now.