I can understand why vigilantes like Batman and Daredevil would prefer to keep their identities hidden - though that doesn't excuse the use of a mask that covers just the upper portion of the face. But it definitely detracts from the "realism" of the Dark Knight Trilogy that Gordon doesn't figure out that the only person in Gotham that could possibly be Batman is, in fact, the Caped Crusader.
And Superman, who operates in full daylight, with the full approval (usually) of local and national authorities and with his face completely uncovered cannot have a traditional secret identity without everyone who has ever seen Clark Kent looking foolish. Perhaps I am jaded - way too many of the Superman comics I read as a child involved Supes going to extraordinary lengths to conceal his identity, using super-ventriloquism and super-hypnosis so that he could safely do battle with underpowered antagonists like the Toy and Terra men. And the character simply doesn't need it - he could still keep a secret identity by using a journalistic pen name (Calvin Ellis?) and keeping his ties to Lois, Jimmy and Perry. The public would know him as Clark Kent, the nice boy from Kansas who grew up to be the man the tourists call "Superman".
It's wishful thinking, but I am hoping the reboot does away with Clark's dual identities. Otherwise we're certain to get a scene in which Amy Adams looks directly at a glasses-free Henry Cavill and asks "Have you seen Clark?"