'The Dark Knight Rises,' the third film in Christopher Nolan's 'Batman' trilogy, won't hit theaters until July 2012 -- but it's never too soon to start speculating on who might be cast and what role they could tackle in the highly anticipated superhero film.

One thing we know for sure is that Christian Bale will once again be donning the infamous cape and cowl. Once you move past that, things are far less clear. Answers may be available soon, though, as Heat Vision is reporting that Nolan has fired off the Bat Signal and is set to audition a series of actresses for prime parts in the upcoming sequel. The names on his shortlist are sure to inspire much debate amongst the comic contingent as it features a mix of established names and rising talent.

Sources close to the project are saying that Kiera Knightley, Anne Hathaway and Jessica Biel are all set to test for roles in the coming weeks. Those actresses will be joined by Kata Mara and Charlotte Riley. Gemma Arterton, who was rumored to be in the running as well, may bow out now that she's signed on to co-star in Tommy Wirkola's 'Hansel & Gretel: Witch Hunters,' alongside Jeremy Renner.

Knightley, Hathaway and Biel need no introduction. Kate Mara and Charlotte Riley, however, are less well known to film audiences. Mara is the sister of Rooney Mara (star of the 'Nightmare on Elm Street' remake and the upcoming remake of 'The Girl with the Dragon Tattoo') and she recently appeared in Danny Boyle's '127 Hours.' Riley hasn't done much film work, but she's the fiancée of actor Tom Hardy – who played a major part in Nolan's 'Inception' and has signed on for an as yet unspecified role in this film as well.

As THR points out, Nolan needs to fill two major female roles. Naturally, one is a love interest, but sources are speculating that the other is for the part of Talia al Ghul. In comic lore, Talia is the daughter of Ra's al Ghul – the villain in 'Batman Begins' who was portrayed by Liam Neeson. Talia is an interesting character not only because she's the daughter of one of Batman's archrivals, but because she's his love interest as well. Bruce Wayne even fathers a child with her in the comic storyline. The 'Batman' books have always portrayed Talia al Ghul as more an antihero than a pure villain, and seeing her added to the film's storyline would be quite interesting since it's not easy to speculate on what kind of role she might play in the film's narrative.

Of the actresses listed, Biel would make for an interesting Talia. The character is described is well versed in the martial arts and with hand weapons – something Biel has experience with from her time making 'Blade: Trinity.' Of course, Knightley and Hathaway seem more than capable of pulling off the role as well. Do any of these ladies strike your fancy, comic fans?