If there was any ambiguity what the moral-psychological wrestle that Kal-El aka Clark Kent aka Superman goes through in Man Of Steel would be, that is now dashed with the first TV spot for the film, which basically gives away the whole story arc in one line of dialogue - presumably delivered right near the end to his key romantic interest before he makes his Big Decision.
If spoilers don't bother you, check out the TV spot below. Of course I could be totally wrong, but everything I've seen until now - and everything they've kept hidden - says no.