This is just the beginning.
I guess Bigbro didn't realize that playing gta iv would be the equivalent of playing gta 3 because this is also a launchpad game for a new generation. All the other crazy wonderful stuff is coming, but first the foundation has to be setup so that the quality is always at the expected awesome level of the franchise. It would have been a disaster to do too much with their launchpad, but you would have to be blind not to see the potential of this new generation of gta games.
Also, this game is a lot darker than previous games have been because it is very important as we all have discovered that kids don't glorify the series anymore. The game is getting increasingly realistic and the last thing mature fans of the game need is another "Special Report" claiming R* is turning the kiddies into homicidal maniacs. I am glad they stripped this game down from the party fest that San Andreas was.