We have three quick pieces of casting news for you today.  First up, Deadline reports that Cameron Diaz and Benecio Del Toro have signed on to co-star in the romantic comedy An Ex to Grind.  Next, Production Weekly tweets that Billy Crudup and Toby Jones will join Zooey Deschanel in Bruce Beresford's biopic Enchantress of Numbers.  Finally, PW also tweets that Kurt Russell, Adrien Brody, and Sharon Stone have come on board Rupert Wainwright's historical drama Waco.

Hit the jump for details on all three projects.

An Ex to Grind is based off Jane Heller's novel, which would have Del Toro as a former star athlete who transforms into a slovenly couch potato after his career is cut short by an injury.  Supported by his waitress wife (Diaz) both before his rise to fame and after his downfall, the wife has now become a big business success.  When she plans to divorce him, she discovers she'll have to pay alimony to support his sad life so instead she conspires to find him a new wife and get herself off the hook.  Of course, when the new woman restores Del Toro's character, Diaz's character wants him back.  Basically, it sounds like a love story between two awful, selfish people.

Enchantress of Numbers sounds like a much better story.  The film is a biopic of Ada Lovelace, a 19th century English writer widely considered to be the world's first computer programmer.  Lovelace was the daughter of the poet Lord Byron and as an adult worked with Charles Babbage, the English mathematician, philosopher, inventor, and mechanical engineer who is credited with inventing the first mechanical computer.  Lovelace's work with Babbage led to the inventor to dub the young countess, "The Enchantress of Numbers."

Deschanel will play Lovelace, while The Playlist speculates that Crudup will play William King, Lovelace's husband, and Jones would play Babbage.  While I think Lovelace makes for a fascinating figure for a biopic, Deschanel is one of my least favorite actresses working today.  Her acting ability appears to extend as far as looking moon-eyed and being sardonic.  Thankfully, Crudup and Jones are a couple of the best actors out there so perhaps there's hope yet for this project. [UPDATED: We've been informed that Deschanel is NOT attached to this project.]

Then there's Waco, which is about the 51-day siege of David Koresh's Branch Davidian compound in 1993 that led to the deaths of 76 people including more than 20 children, two pregnant women, and Koresh himself.  Director Rupert Wainwright (Stigmata, the 2005 remake of The Fog) described his plan for the film on his website:

WACO will be the first narrative feature film to explore the events of the ATF raid on Mt. Carmel, TX, the 51-day siege that followed, and the devastating compound fire that resulted in the deaths of 81 civilians. The movie cuts between ATF special agents, FBI Negotiators, the Davidians on the inside, the tactical Hostage Rescue Team leaders, and the political machinations in Washington DC.

Wainwright also wrote the script along with investigative journalist James Hibberd.  Michael McNulty, director of the award-winning documentary Waco: The Rules of Engagement, was been brought on board as an consultant.  No word yet on which roles Russell, Brody, and Stone will play.