Dunno how reliable this is, it's from a couple months ago, thought i'd fire it up anyway
http://www.darkhorizons.com/news05/051012g.php
read in quite a few places that michael Keaton and Ryan Reynolds are the current favorites to play the joker. I find it rather amusing that when i realised they were gonna do another Joker movie a commented that if he hadn't already been Batman Keaton would have made a magic joker.
I dunno how likely he'll be to do it as i believed he's lined up to play Jigsaw in the Punisher sequel.
It's all very ahead of time so i'm taking everythin the now with a pinch of salt.
oh aye and Warner Bros have penned in june 20th 2008 as the release date for the film. Don't know quite how they've managed that when it's not even started production and whatnot but there ye go.