Sorry but there's no fact here, just opinion. All TDK did was have a great story. That's why it's so good. It is a great film. Iron Man also had a great story and was great. But to say either raised the bar quality wise is just not true. Before TDK films were being shot the same way TDK was and they are still now. Just because a couple of scenes were shot in IMAX doesn't mean raising the bar. Actually, I would say that Nolan senseless stubbornness against CGI actually held back many scenes from greatness. Any intelligent director should know CGI can be put for good use. TDK was lackluster in terms of visuals in many ways and the best we got was the truck flipping and it was awesome just because....it was done for real? Err, it's a movie no matter what so.
I think it's safe to say the film did raise expectations general audiences will have for this genre in many ways. It's received eight Oscar nominations, was hailed by critics everywhere, did massively well, fans of the character adored it, and it really spoke to a generation of filmgoers like nothing else we have seen lately. When did that happen to a comic book adaptation before? Possibly with Superman, I'm not old enough to remember that far back, but TDK WAS something special for a lot of people.
I don't think CG can capture the thrill of old fashioned stunt work in a film that is supposed to be grounded in reality. The truck flipping in TDK was a lot more impressive than the CG one in Terminator 3, as an example. Realistic stuntwork would make the Phantom feel more grounded, like he (usually) is in the comic.
The CG enhanced stunts in Quantum of Solace too: well made, but some of them took me out of the movie simply because they didn't look quite "real".
I liked Iron Man, it's an entertaining film that was also very funny in places, but find it tremendously overrated by many. Now there's a film that didn't do anything new at all; it followed the Rules of Comic Book Filmmaking Handbook in every way, with exactly the same formula, build and way of storytelling we have seen many, many times now. Still, it got away with it, it made a huge profit and people all over the world loved it.
Let's also keep in mind that Watchmen will very likely be another film that will make a strong mark like TDK if not more, and this film, while it will have a powerful story and message, visually it looks more "fantastical" than TDK. So, this could also be a way Tha Phantom could go. That kind of "300" look.
Well, maybe, but I'd still probably prefer something a bit more down to earth in terms of look. But who knows what they'll come up with.