Mania.com is reporting that their sources have cited Rachel McAdams as in talks with the film's producers to take on the role of Felicia Hardy, also known as Black Cat. If you're unfamiliar with the character, she is a sometimes good, sometimes bad cat burglar who, in addition to being a possible love interest of the web-crawler's, tries to use her less-than-legal prowess to break her father out of jail. It would be an interesting spin to have villainess for part four, but it's unclear at this point as to whether or not the film's Black Cat will ultimately be friend or foe.
A bigger shake-up to the film's line-up could come by way of the second bit of Mania's news, which stakes that the producers are also currently out casting a male villain. Assuming Raimi hasn't already broken with his desire to keep the baddies solo, this would mean that Dr. Curt Connors is not fulfilling his destiny as The Lizard after all, despite Dylan Baker confirming he'd be returning in the role. It's all very fluid and salty at this point, but if Mania's sources are indeed correct, Spider-Man 4 has either multiplied its villains once again or kept The Lizard caged until a later date.