I think that Bane, Tate and maybe Gordon will find put Bruces identity but I dont think all of gotham will know, but thats just me.
The reason why I think bruce's identity will be revealed;
Bane clearly sets the poor/rich divide off, when he outs Harvey Dent as the corruptible killer that he is. He tells those who struggle to live in gotham to take back their city from the rich and wealthy who drink and party their city dry, while the others work backbreaking thankless jobs for a measly life.
That was a major point in Batman Begins and a major point in the death of Bruce's parents. Joe chill wasn't a hired gun, nor was he a thug, he was a man on the edge of desperation (or so we are meant to believe) BB showed us a clear divide between the people that abuse the city for it's wealth (Falcone, the judge, corrupt cops) and those that are forced to live in poverty because of them (the narrows). I think this film will take it further by showing the poor and helpless actually helping themselves and fighting back against the rich, the politicans, the government. A city tearing itself apart just like how Ra's wanted, and bane manages to set this off by showing how the best of them, the one government official that seemed like he cared, that truly sacrified himself to make the city better...was nothing more than another corrupt official. That is enough to cause a scene like the one we saw in the trailer where people violently ransack some poor guys posh apartment.
In the end I believe Bruce's mansion will get raided, seeing as he is in their eyes "the worse of the worse" a rich playboy who was born with a silver spoon in his mouth, who lives in excess while the good people of gotham starve.
Therefore i can imagine the one person who can finally unite the two classes, who can finally inspire the city to do good is Bruce Wayne. Harvey Dent was supposed to be that guy, the Harvey Dent Act seems like a band aid, clean streets but unhappy people...which eventually leads to crime, and then we are back to square one. Bruce Wayne is the very epitome of gothams aristocracy....to reveal that he was all along doing the most thankless selfless job in Gotham city, is a shining example of what the people of gotham needed.
The hero it deserved, but not one it needs right now....maybe TDKR will finally show a time when he is finally needed and eventually Bruce can be the hero his father always was, not as just as Batman, but as Bruce wayne as well.
Just a thought. Stolen and built upon from better people here.