I think in the Dark Knight Gordon has an inclination that Bruce the playboy was a facade (or that he was indeed Batman). His first thought was that he was trying to protect the armored car, which he was. There's also that subtle, patronizing way he goes about calling Bruce out for not watching a lot of news when everyone in the city knows that the hospitals are in danger. Almost a *wink* *wink* moment.
By TDKR though, they completely throw that idea out the window and abandon it. Gordon literally has NO idea and is genuinely surprised when Batman reveals himself. We even see his face, "whaaa Bruce Wayne? DERRRP". That's another problem I have with TDKR. The character of Gordon completely devolves from what we've seen in the beginning into this chuckle headed, incompetent shell of a man. He was with Batman at the characters conception back when he was just wearing a survival suit and a skimask with a paperclip gun. Being a great cop/Detective/Lt. Commissioner, I don't care what he would like to think, he'd have atleast some awareness of who he was by his nature alone. That ambiguity in Gordon and Batman's relationship is great, but to say, "oh, Gordon doesn't know or care" is a huge cop out. It makes him look stupid and completely oblivious.
He didn't put two and two together when this "nut" was so eager to push an "assistant DA brave enough to prosecute . . . Rachel Dawes"? Or Bruce Wayne and Batman's persistent admiration of Dent after he's convinced at the restruant? Or how clearly affected Batman was at the mere mention of Rachel in the interrogation scene? Or Batman CHOOSING "Rachel" (not Ms. Dawes like the script) over Dent? Or the day that everyone is looking to kill a Wayne Enterprises
employee who knows who Batman is
(Gordon acknowledges this with a snide remark about "Batman saving" Coleman Reese), then minutes later, Bruce Wayne saves the day by purposely getting into an accident and smashing his lambo?
C'mon. You don't have Gordon say, "I never knew and I don't care". Atleast have him smile at the end of their last exchange instead of, "B-B-Bruce Wayne??". No duh dip ****.
He's just as dumb as Selina.
I'll give credit where credit is due. As much as I don't like Blake as a character, he is
the smartest character in the movie. It's ironic because he's the least established AND has the least involvement with Batman/Bruce Wayne prior to the plot that unfolds in the movie.