I'd certainly support some mafia themed Rockstar game focused in 1920's on wards especially if it's heavily influenced by Boardwalk Empire and it can include bootlegging, importing of illegal booze, greasing politicians, illegal gambling and prostitution.
Mafia is great and I know Rockstar would do great with it but they can just do their own thing. 2K have the potential and I'd love to see them use it to the max.
great idea! since R* never touch the 20s prohibition era, it would be great if they make an openworld game based on that era. rather than GTA series, i prefer new IP for this kind of game. but still, i want R* to make a game that focus on the story of italian american mafia, set during the 60s