Nolan is not going to do catwoman. 2 costumed character crosses the line on his "realistic" portrayal of Gotham. Plus he isnt the type to just introduce a catwoman without explaining how she became like that and how she got her "powers". Joker was different because a mysterious past was his essence and he didnt have superpowers. Explaining her will take a good chunk and with all the problems and potential for plot progress left for batman on a personal level, catwoman isnt viable IMO. It would work if selina kyle is introduced as a love interest and just a woman not catwoman yet but seeing how this is probably the final flick, introducing selina and not making her catwoman would kind of be lame. I am liking the riddler with a creative and radical interpretation that completely contrasts his personality from the joker (and no POTC Depp).