Nolan said that the proloque for 'Rises' was, and I quote: "Basically the opening of the film". Basically? It might be shortened down a bit in the beginning. I'm talking about Gordons speech. it felt weirdly rushed, imo. 
I could still see it opening with the icy bat-symbol as shown. Than fading over to this memorial day in Gotham, held in honor of Harvey Dent, SHORTLY after the events in 'TDK'. A nice calm, not rushed opening, with a longer beautiful speech to Dent held by Gordon. He than ends it with the words, "I believed in Harvey Dent".....than.....BOOM! (No, seriously. A boom is heard) and in the same exact instant, we cut to black. A few seconds of nothing goes by. Than, on screen it fades up: "EIGHT YEARS LATER". We first than open up to the plane hijacking sequence, and CALMLY, the audience is tuned in to "TAKE OFF!"... But that's just a dream of mine.