Doesn't bother me. As popular as Joker is, he's still fucking awesome. And with Nolan on board, the film will be great. He hasn't made a bad film yet, and I don't see him starting now. The only problem is Ledger living up to Nicholson. Nicholson worked so well because he just looks insane. All of his best roles are when he's fucking crazy, and if you have ever seen him in an interview in real life, you'll notice that he wasn't acting in the film. Ledger has a lot to live up to, but Nolan knows what he is doing, and with such a superb supporting cast, I think that Ledger will be fine. Just fine.
Edit: I would much rather they keep Robin out of all of the films. Can't stand that prick.