Keep in mind, this is all speculative. Christopher Nolan is now currently looking at Anne Hathaway, among others, for two roles in "The Dark Knight Rises". One role being a love interest, the other being a villain.
This picture has surfaced courtesy of Yahoo, that shows Anne Hathaway dressed up similarly to Catwoman, who obviously would make sense for the "female villain" being rumored now. Really, there is only Catwoman, Talia al Ghul, The Huntress, Harley Quinn and Poison Ivy that could really appear here, and Catwoman is most likely by far both in realism and overall tone of Nolan's Batman movies currently.
Does this picture really mean anything? Maybe not, but it is a pretty big coincidence then and it is probable that at that time Hathaway had already been in talks with Nolan.
Talia al Ghul also could be the villainess since her father, Ras al Ghul, appeared in 2005's "Batman Begins" played by Liam Neeson. But seems, again, most unlikely compared to Catwoman.