What I don't understand is why fans of the '89 Batman are shitting their pants and are so mentally raped by this.
I'll be a bit more blunt here than I was on GAF.
As a fan of the comics, the look is wrong. The Joker is supposed to look visually insane, they have just turned him into your average mutie-looking freak. I understand Batman Begins got a lot of credit for being kinda gritty, but they focused on the wrong aspects of the character here.
But I'll reserve final judgment until we see more.
I agree with this. I loved the makeup job they did on The Joker on the '89 Batman, even though I'm not very fond of that movie (the casting was okay, but there were serious script problems).
I would personally have preferred if they'd tried to emulate Conrad Veidt's look in The Man Who Laughs, which is what Bob Kane originally based The Joker on anyway.

I'm not going to make any judgments until I see more, though. To me, the new look reminds me of Kakihara from Ichi the Killer.

It looks like they're going for the "crazed serial killer with a clown motif" thing more than the " insane clown prince of crime" thing.