The vocal cast has been revealed for the animated adaptation to Geoff Johns' and Gary Franks' Action Comics Brainiac story.
Source: First Look: Matt Bomer Gets Animated for Superman: Unbound
Though still a while away (The Dark Knight Returns Part II hasn't even been released yet), Superman Unbound's voice cast has been officially revealed, along with two images from the movie. The movie will adapt the Geoff Johns/Gary Frank Brainiac story that reintroduced the villiain in a major way into the DCU (until two years later when DC decided to relaunch Superman yet again and Grant Morrison then brought the villainous Brainiac back. Though I guess, given Morrison got his All Star Superman adapted, this was the best DC Animated could find of Johns' Superman work).
Voicing the Man of Steel will be Matt Bomer (White Collar), and playing the villianous Brainiac will be John Noble (Fringe). Filling out the remainder of the cast will be Stana Katic as Lois Lane and Molly Quinn (Castle) as Supergirl. The movie will be directed by James Tucker (Batman: The Brave/the Bold).
As for the plot of the movie, Tucker had this to say of it's lead villain:
"He says what he's doing is the name of science and ultimate knowledge, but really he just wants stuff and he doesn't want anyone else to have access to it."
As for the secondary subplot, no word yet if the role of Jonathan Kent has been cast or even if they'll be adapting that important story beat. However, one subplot confirmed is Superman struggling to balance his life as Clark Kent (terrifed that his enemies might find out his secret identity along with being over protective of his niece Kara).
Superman Unbound will be released on DVD and Blu Ray sometime of the summer of 2013.