I think the difference between Nolan's versions of Batman and Tim Burton's films is that Nolan creates a much darker and gritty atmosphere compared to what we've seen in the past. I mean Tim Burton's films were more comic book-like than compared to this new series of Batman movies. Given there were certain dark elements to it, Nolan is taking a completely serious approach to the franchise and this new Joker is probably the result of that. The Joker himself has been portrayed as pretty much two different people; the sarcastic psychopath that likes to play around such as the version in the 90's Batman cartoon and then there was the cold-blooded murderer who has a dark humor that isn't like what some people are use too. In this case it's the latter with Nolan's movie and the look they've given him is much more ugly and gritty as I said.

Now, honestly I'm more use to what everybody is use to, the funny Joker like that in the comics or cartoons. I have my own doubts about this movie, but seeing as I really liked the first I'm kind of glad Nolan has pulled away from JUST the comic-book feel and focusing on the darker elements on hand. If the same had been done to the Spawn movie instead of the popcorn film there is now then it would've been a lot better. I think that's what plagues comic-book adaptations in general because people want to see a more realistic perspective to the comic than just the typical stuff you saw for kids. It's sort of like how I went from Saturday morning cartoons to anime because there are more of it that's much deeper than a hero saving the day and some villain who escapes jail every week. The more adult theme to it appeals to me and other people.