Note: A 'pre-vis' scene refers 'previsualization' filming. The advantage of previsualization is that it allows directors to experiment with different staging and art direction options such as lighting, camera placement and movement, stage direction and editing - without having to incur the costs of actual full-blown production filming."
The website goes on to report that
"The Transformers 3 is now in production and auditions for principal actors are taking place. Director Michael Bay has signed on to direct his third Transformers picture. Pre-shoots start April, 2010. The filming locations are set for Los Angeles, Chicago, Washington, D.C., Florida, Texas, Africa, Moscow and China. Principal photography will run from May 17, 2010 through July 1, 2010. Release Date: July 1st, 2011.
See the post titled Headshot and Resume Information regarding how to submit for acting roles."
Though un-official the same site also lists the following under story:
"Shia LaBeouf and Megan Fox return as Sam Witwicky and Mikaela Banes in "The Transformers 3". A darker more introspective journey into the Transformers universe and their origins on Cybertron. Peter Cullen also returns as the voice of Optimus Prime. This 3rd installment in the series "won’t be as robot-heavy and there will be fewer explosions, as the film gets more into the robot character. The last time (Transformers: Revenge of the Fallen) you kind of met a few of the robots. In 'The Transformers 3' you’re gonna get a much cooler landscape" according to director Michael Bay. There is also preview footage of the possibility of Unicron, the planet eater, in this sequel."