If you were expecting a bunch of information to be revealed about Mass Effect 4 at this E3, then it looks like you are out of luck. Although EA did reveal some new details, these are just too vague and scarce to satisfy fans.
According to the game's executive producer, Casey Hudson, Mass Effect 4 will take place in a new region of the universe, with players taking control of new characters. Players will have a vast world to explore, full of new places to discover, people to meet, and stories to tell. In addition, Bioware also took this oportunity to release the first concept footage of the title.
At the moment, platforms and release date for the title are yet to be revealed.