According to the Electric Playground, Rockstar San Diego is looking for.developers to create a new open world game. It is unclear if the project is a new Red Dead game, or if it's a new Midnight Club game. Hopefully it's Midnight Club.
It would be highly unlikely its a Midnight Club game as they pulled the plug on the series. I guess they don't like putting effort into making a huge open world if it isn't going to sell by the bucket load.