fu*k this game is going to take FOREVER for a person like me who tries to get everything in the game
sounds stressful but amazing at the same time
my head is going to explode
If they manage to do the size of the map justice with side missions and sh*t, then one campaign could take as many hours as Fallout 3's. Red Dead Redemption showed promising signs for this game in that respect..
Edit : Although.. LA Noire was the exact opposite - huge map with nothing to do in it. I know that Rockstar took more of an 'executive producer' role during the development of that game, but they had influence regardless.