DC Comics made the announcement to Entertainment Weekly that Superman and Wonder Woman will officially be a couple, starting with Justice League #12. "This is the new status quo," League writer Geoff Johns intimates. He's clearing away any speculation that this is a one-and-done kiss or an imaginary story. Jim Lee, Justice League artist and DC co-publsiher, knows this news will draw publicity, "Hopefully, this will raise a lot of eyebrows." Mine raised!
I can kinda see Bruce Wayne and Diana Prince as a (short-lived) DC power couple, but not Superman; not Clark Kent. Here's the thing -- Superman enjoys predictability. Now, that doesn't mean he doesn't enjoy excitement or that he's boring; it means he likes to interact with people whose motivations and behaviors he completely understands. Lois may be headstrong and spontaneous, but he can predict that behavior from her. It's comforting. This is why he's able to handle Lex Luthor, while characters like the Joker completely unnerve him.
Wonder Woman is simply too unpredictable for Superman, and I think he's always been slightly apprehensive of her because he can't quite get a handle on her. I'm not saying they would never hook up. Often, men and women who work closely together can form attractions, etc, blah blah blah; I am saying that, from my perspective on Superman, he wouldn't let things get very far once he took into account how Wonder Woman typically does whatever needs to be done in that moment, sometimes leading to seemingly erratic, flexible ethics that Superman would find uncomfortable (this is the woman who killed Maxwell Lord, after all).
There's a 90's movie called If Lucy Fell, in which an NYC artist lands a tryst with his unattainable dream girl only to discover that the fantasy he'd created with her in his head was so much better than the reality. To me, this is a good analogy of the fan relationship to the pairing of Superman & Wonder Woman. We'd like to imagine what it would be like if they'd hook-up, but the reality is simply not the same as the fantasy.