Man of Steel was an interesting take on the character, but, I think, an unfinished one. It clearly sets Kal-El on a trajectory to become Superman, and he's almost there by the end, and all the ingredients are in place (it even explains why he doesn't kill: having done it once, he knows it's so painful to do, even when as justified as it can ever be, that he'd rather find any other way), but when two and a half hours of explosions conclude, he has only just become Clark Kent.
Let me explain what I mean by that. "Welcome to the Planet" is a good ending line because of the obvious double meaning: the alien Kal-El has accepted Earth as his home, and no longer feels alienated from Earth society. So I use his Earth name to refer to him after that point, and his Krypton name before then.
It has a lot of very bold plot beats, too. When Super-9/11 is happening in Metropolis and misguided American missiles are blowing up terrified civilians trapped in collapsing buildings, our hero saves the world by flying away and breaking apart a machine in the middle of the Indian Ocean where there's nobody around to see. That's a pretty heavy statement. An unfortunate consequence of that decision, however, is that there's a real shortage of shots of Superman conspicuously saving people, inspiring the hope that the not-an-S stands for, that sort of thing, and (even at the risk of turning it into Superman Returns-style hagiography) that's kind of the shot that you really want to see in a Superman movie. It's conspicuous in its absence.
This is a film about how Superman is terrifying. Which, y'know, he kind of is. Kal-El is afraid of the world but learns to have faith it, and it ends with him asking the world to overcome its fear of him in the same way. Perhaps it feels unfinished because at the end there still isn't a Superman who's a symbol of hope, or perhaps that's exactly the point about the nature of faith and proof.
I was expecting that Man of Steel 2 would finish the story, with Lex Luthor capitalizing on the fear of this alien and turning the world against him, to which he would respond by finally becoming Superman.... But that was before they announced it would be a Justice League movie instead. Now I'm not quite so optimistic.
