All i can tell you about the guy in the bottom left is that he is a "big shot" in the city, C.E.O. of GetaLife insurance who "the character" works for and later betrays.
For some reason I just don't don't believe that.. The GTA cover has a big "IV" on it.
like i said, its just a prototype, we probably wont even use it, but its kinda neat to see where the game is going, with some characters not shown in the preview.