IGN FilmForce has an exclusive revealing of the casting for many of the human roles in The Transformers. Jon Voight is thought to play Keller, Michael Clarke Duncan as Figueroa, Josh Duhamel as Lennox, Bernie Mac as Bobby Bolivia, Tyrese as Epps, John Turturro as Simmons, Rachael Taylor as Maggie, Megan Fox as Mikaela, Travis Van Winkle as Trent, and John Robinson as Miles.
All the names in italics, are not the real names of characters but but have been used to keep the film under-wraps. For example, Shia LaBeof is playing Spike Witwicky, not Sam!
Also for now, this should all be taken as a rumour as all the information came from many unnamed sources.