I would love to see street gangs return, The Ballas, Grove Street Families, Los Santos Vagos, Varios Los Aztecas... Dynamic gang-fights throught LS would be awesome. I would really love to drive into the Grove Street Culdesac and see The Johnsons house, with GSF members hanging around... I really hope there is a gang system where you are able to take over territories like in SA, especially with RAGE physics. But if the protagonist is Caucasian as he sounds in the trailer, I doubt he will be a member of these gangs. Maybe a new gang will arise, who knows.
How do you feel about Street gangs in Los Santos? In my opinion that's what makes the city what it is.