Brad Pitt and Will Ferrell in 'Oobermind,' Robert Downey Jr. out

In somewhat of a surprise, Will Ferrell has replaced Robert Downey, Jr. in the new DreamWorks animated title "Oobermind."  Variety also reports that Brad PItt and Jonah Hill have joined the already cast Tina Fey in the superhero-themed actioner. 

"Oobermind" centers on a supervillain who thinks all his dreams will come true once he defeats his longtime rival, the heroic Metro Man (Pitt).  Instead, he finds life quite boring without a super-powered sparring partner.  To keep things interesting, he creates a new superhero, Titain (Hill) who turns out to be more of a bad guy.  This forces Oobermind to switch sides and show a heroism he's never had before.  Fey voices the news reporter tasked with keeping track of the superhero/supervillain back and forth.

According to the trade, Downey, Jr. dropped out because of scheduling conflicts. Sort of an odd issue for an animated film, but anything is possible.  Tom McGrath, co-director of the "Madagascar" franchise , will helm "Oobermind" solo.

The quartet are no strangers to animate fare.  Ferrell has "Curious George" on his resume, Fey participated in this past weekend's "Ponyo," Hill is the leading voice in "How to Train Your Dragon" and Pitt participated in an early DreamWorks Animation effort, "Sinbad: Legend of the Seven Seas."   

"Oobermind" is already has a Nov. 5, 2010 release date.