First it was Jamie Kennedy and now a new casting rumor has Grey's Anatomy's Patrick Dempsey (aka McDreamy) joining the cast of Transformers 3.
The information comes from an interview with the actor by Bol Noticias, a Brazilian website. The Google translation indicates that when asked what his next movies are Dempsey responded, ""Flypaper," I start filming later this month, and "Transformers 3", which play a character that is far more "dark" than others."
One interpretation of "dark" is that Dempsey has been cast in a villain role of some sort. No idea if that means a human character or a Transformer voice role. Thanks to Aaron for the link.
Update: EW's Hollywood Insider has confirmed with Paramount Pictures that Patrick Dempsey has been cast as a human character in Transformers 3. He "will Megan Fox’s boss in a role that is 'significant to the plot'." Thanks to TigerClaw for the link.