Now that Henry Cavill (The Tudors) has been cast into the high profile title role of Clark Kent in the upcoming Superman reboot, rumors are pouring in hard and fast to fill in the supporting cast. Previous rumors indicated that Diane Kruger, Rosamund Pike and Alice Eve were gunning for the role of Ursa, a Kryptonian villain, and the latest speculation puts some of Hollywood's best as contenders for Ursa's leader, General Zod.

While we wait to find out who will play Ursa and if either Viggo Mortensen or Daniel Day Lewis will be chosen to play Zod, we do at least have one more official Superman cast member to announce. Warner Bros. has just informed us that Diane Lane has officially signed to play the motherly Martha Kent!

The beautiful and talented Lane hasn't been too busy in the last two-three years but still played key roles in last year's Secretariat and in Jumper, Killshot and Nights in Rodanthe in 2008. She previously received an Oscar nomination for her performance in 2002's Unfaithful and makes for an excellent addition to the cast of Zack Snyder's take on the Man of Steel.

On the casting of Lane, Snyder says:

“This was a very important piece of casting for me because Martha Kent is the woman whose values helped shape the man we know as Superman. We are thrilled to have Diane in the role because she can convey the wisdom and the wonder of a woman whose son has powers beyond her imagination.”

We know the film, which is based on Chris Nolan's and David S. Goyer's story, will not focus on Superman's origins but we at least know that Clark's parents and the iconic Kent family farm will have a role to play. Assuming that Kevin Costner's rumored role is that of Jonathan Kent, Warner Bros. is making great casting choices thus far.

Superman: Man of Steel (not yet officially titled) is produced by Charles Roven, Emma Thomas, Christopher Nolan and Deborah Snyder, and is set to hit theaters in December 2012.

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