It is a nothing more than a rumor but that sounds cool to me. And as a bonus, whytemyke called this earlier in the "Katie Holmes dumped from batman sequel" thread:
Here is link to the rumor:
http://aintitcool.com/display.cgi?id=20563
whytemyke said:How about Joker? Honestly, I think Jim Carey could be an awesome joker, but his appearance in a former Batman movie precludes him from doing anything in these ones. Jude Law may be a really cool choice, but they'd have to fuck him up so his face doesn't get more press than his role does. You've gotta have someone that's deadly serious...that's what makes joker so awesome. You know who'd be AWESOME, but they'd never get? Sean Penn. It'd be sweet to see him try something like this. I also liked it when someone mentioned Adrien Brody for the role, too.
Here is link to the rumor:
http://aintitcool.com/display.cgi?id=20563