Now that I've had some time to digest this, I actually think a lot of it is an improvement. I'm not crazy about the totally bleak, grey palette they've used to re-color the Joker, but the rest of the changes are for the better and even that panel has a lot of perks. I love the differences in the way his eyes are colored - they're twice as piercing and haunting with the new colors - and although I don't agree with the decision to nix the purple gloves, I have to admit the lighter color does a much better job of bringing out his hair. The gleam of his lipstick and improvements in the coloration of his teeth make a big difference, too. Also, this is a minor thing that I only really noticed because I know the difference between the printing processes involved, but take a look at the shade of black that's used on his head's shadow when it overlaps his button-up. In the original coloration, it's a mildly different tone than the shadow that carries through to his vest, where in the new version they're identical, which I think brings a lot more the composition.
I think maybe with a bit more saturation in his wardrobe, I'd be universally in favor of the new colors, but that's a major stumbling block. As is, it's like most of the scenes were run through a filter and clarified significantly... and I love that Gordon has abandoned the fluorescent yellow overcoat and hat.
Something a bit more like this...