Background
I am really hoping Take Two makes a game like this, he hasn't really nailed all that much down. Even though he insists that the game start at the trial, not showing anything beforehand, you could certainly place flashbacks throughout the game, and it could be hilarious if done right.
Aside from the suggestions made in the comments in the link, I think it would be awesome to team up with and older Tommy Vercetti on at least one mission, and have Tommy say something along the lines of "Yeah, I was watching my newphew play one of those videogames the other day, gave me the creeps, I mean, I watched him beat a woman to death and take her money. What kind of monster does that?"