Batman Began

I have been reading up on a lot of rumors about the supposed sequel to Batman Begins. Some of the talk says that Joker isn't going to be in the sequel at all, but most seem to say he will be.
These are the candidates that I have seen mentioned
Sean Penn
Paul Bettany
Lachy Hulme
Mark Hamill(Luke has been scrapped due to age)

Of all of these, I believe Paul Bettany would do the best job. I have liked every role Bettany has played, from Chaucer to Opposite Russel Crowe in Master and Commander. I beleive he has the chops, and I believe the entire franchise would benefit from him. The only thing i would ask is that if we see Joker's father, or anyone dealing with Joker-before-he-was-Joker, that Jack Nicholson plays that part.
Jack Nicholson as the Joker is one of those great movie memories from my childhood, and the only reason the first batman was worth watching(as apposed to the others that sported such horrible things as 1) penguins wearing missiles 2) neon lights on the batmobile 3) nipples on the batsuits[these are by no means the ONLY reasons the latter three batman movies sucked...])

On another note, I really enjoyed Batman Begins. If the sequel is to be on par or better, Paul Bettany is the way to go.