I found where I read it. It was all on the Wikipedia page for the Batman film franchise:
http://en.wikipedia.org/wiki/Batman_...ries%29#Future
It suggests that The Riddler as well as Catwoman could be potential characters. It also suggests that Nolan doesn't want to use the Penguin or Robin. And that some other producer doesn't want to use Catwoman. So who knows? As far as Two-Face goes, it says that Eckhart is confirmed for the third movie, but if you go to the source link about it, it is just a statement from Eckhart that he would love to appear in the third movie. Again, who knows?