The guys at Red Cup Rebellion have sources saying that Arkansas State head coach Hugh Freeze will be offered the Ole Miss job. As there's no reason why he'd turn it down, that means he's probably your next Rebels head coach.
The Ole Miss Rivals site is saying the same thing, so it's probably solid. Freeze was Michael Oher's high school head coach in the days of The Blind Side, and he's been on the Ole Miss staff before. He's from Mississippi and has won everywhere he's been, so he very well could be the fit they've been looking for.