Rumors started by The New York Times and Julie Newmar had Angelina Jolie vying for the role of Catwoman (which would be totally hot. But sadly, untrue.)
Instead, it seems that Christopher Nolan has someone else in mind. It also seems he is off his nut.

The facts: Maggie Gyllenhaal and Aaron Eckhart signed on for two Bat-pictures.
A source close to Maggie Gyllenhaal confirmed that she’s
excited about the next movie, “why else would she, or Katie Holmes for
that matter, take on the thankless roll of Rachel Dawson? After Katie
left the role, they could’ve created a new character. But that wasn’t
part of Nolan’s plan. This is the trajectory he’s planned for Rachel
since the first movie. Not only is Maggie contractually obligated, but
she’s already getting in shape for Batman 3.”
“It shows Christopher Nolan has imagination that he didn’t cast me
as the villain,” said Gary Oldman (Jim Gordon), “since somehow I got
into this thing of always playing these eccentric characters. But I
always liked the Riddler. I liked the whole Riddle aspect. I loved the
suit. I thought the suit was pretty cool. You have to be pretty fit,
though, don’t you, to wear the Riddler outfit?”
Same for
Catwoman’s outfit, but Maggie Gyllenhaal (Rachel Dawes) is willing to
try it on for size. “I liked Michelle Pfeiffer as Catwoman,” Gyllenhaal
said.
“There was alaways a Batman movie out in the summer when I
was growing up, but I usually couldn’t care less. But doing this movie,
I started to get it. I felt it. I understood.” Especially when she’d
had a scene where “Batman would save me from certain death and envelope
me with his cape,” she said. “I thought, ‘Oh, that kind of feels good.’
”
And since Catwoman is sometimes saved by Batman, Gyllenhaal
said she wouldn’t mind borrowing one of her nine lives, just to relive
that experience. “Yeah!”
Sigh. If this is true, I will cry. Catwoman should be sexy. Maggie is about as sexy as a houseplant. I like her, but she oozes good girl.