Can Heath Ledger Be Replaced As The Joker?

I thought I'd like to share what I found to be a very interesting article I found at The Movie Blog, concerning the possibility of Heath Ledger being replaced as The Joker.

The writer made a few very interesting points, one being that there are better actors out there than Heath Ledger, and another that the nature of reality is that achievements that people say are unbeatable are always eventually surpassed. We may say that no one can play The Joker as well as Heath Ledger, but how can we know until another great actor gives it a shot?

I'd elaborate, but I couldn't do the article justice, so check it out here.