Dreamworks Animation SKG, Inc. and Paramount Pictures announced today the cast for Monsters vs. Aliens, the first movie produced with Dreamworks' Ultimate 3-D technology:

Reese Witherspoon, Hugh Laurie, Will Arnett, Seth Rogan, Rainn Wilson, Stephen Colbert, Kiefer Sutherland, and Paul Rudd will lend their voices to this animated reinvention of the classic 1950's monster movie.

Witherspoon plays Susan Murphy, a California girl who grows to enormous proportions after being hit by space junk. She is soon rounded up by the military and taken to an installation where other monsters have been taken over the years. Their confinement is ended when a mysterious robot lands on Earth, and the President calls for the monsters to battle the alien force. 

For more information about the movie, please see the Information Page for Monsters vs. Aliens. We have two photos from the movie so far, and I'm sure that a trailer and other information will be coming soon. 

It is scheduled for release on March 27, 2009.

Source: Dreamworks Animation SKG, Inc. Press Release