Personally, I don't see anything wrong with the Grand Theft Auto games. They're fun, and they're only as violent as you make them. Sure, you are given some fairly violent missions such as 'go assassinate somebody', but for the most part it's nothing that you don't see in your average 18+ rated movie. Let's not forget that GTA is 18+ rated.
Everything else such as killing prostitutes, clubbing random pedestrians over the head with baseball bats and whatever else the media has concentrated on is 100% down to the player. They're not told to do it, nor is it documented in the manual. The game simply lets them do it, and that is an important point that I feel far too many people miss out.
That said, what Rockstar is doing with Bully I don't approve of at all. With bullying being a genuine concern for a lot of children and parents, painting it to be even remotely positive is a seriously irresponsible thing for anybody to do. Rockstar know damn well that younger people will go out of their way to get hold of it due to its association with schools, and this is blatantly nothing more than a "We're doing it because we can!" move by Rockstar. I hope it backfires.