Exactly Heath wasn't a recast and his Joker was completely different from Jack's. Unless the Joker is going to go through some kind of drastic change that is explained on screen there is no way IMO to recast him. The recast of Rachel Dawes only worked because Katie Holmes and Maggie IMO sucked about the same and there's no one who I have ever heard of who was really a fan of that character enough to care that she was changed...and
Spoiler:but recasting the Joker would be a whole different deal. The person would have to play the character almost exactly as Heath did for the continuity to believable and to get a similar response and that will never happen IMO. The best they could do is a poor imitation and I'd rather he didn't show up than to get a second rate Joker myself.
she died so who gives crap?