Enemy AI is now weapon and class-specific, so an enemy drone given a shotgun will try to move in close, while one with a sniper will attack from a distance. At tougher difficulties enemies will use more sophisticated weapons and throw grenades.
That info is E3 old. Anyway I really doubt the Facebook is real HVS Tony and David Pellas (http://leakybattery.wordpress.com/2010/08/07/vehicle-rumor-debunked/) didn't know anything about that page.
He got back to me and said a lot of the information is true but also a lot of the info is wrong. Either there's a miscommunication or it's much more likely that it's run by a fan claiming it to be official.
Call me Silly_Tunic!!! http://leakybattery.wordpress.com/ (mah videogame blog)