It would only attract kids, the possible classes are their, but the main audience will say fuck that... Leveling driving skills? It isn't a racer and never will be considered one. Every class boils down to a gangster who fucks people up with guns or blunt objects: neither which is enough to differentiate a class. The closest they could do is a GTA SA type skills system and have it as the multiplayer options for the next GTA, but it wouldn't be a true MMO and no one will pay for it.
Be realistic:
What Classes could they have(not that they would work/be played)
-Gangster
-Gunsmith
-Bookie
-Mob Leader(imagine this would be something along the lines of a rank over a class
Can you think of others which wouldn't be some sort of ripoff of the 3 I listed?
How would weapons work? Their would be near no difference in weapons if it is left as an open shooter, as I cannot see GTA imploring RPG style combat.
It simply should be kept out of an MMO status IMO.
