The beauty of Bully is its story line. Rockstar did a amazing job of taking a open world game to a school. It depicts class conflict, corrupt education system, emotion, bit of sex, friendship and what not. Also, the way each of the charecters are developed, you feel you are back to your boarding school days and relate to them. There is no comparison with GTA series even though RS uses the same engine. GTA should actually now stop coming up with sequels as after san aderas and vice city stories the other ones look forceably streched to PS3 platform.
As for sequel of Bully-why not once more at least. I like the idea of inter school rivalries. Jimmy becomes the hero of bull worth and now there are two or three more rival schools which compete with each other. There are gangs there as well and there are often fights. Jimmy and his friends (leaders of different gangs from Bull worth) compete in racing, boxing, elections, debates, soccer matches, inter school championship etc in the day time and set out to do the naughty things in the night. When jimmy befriends a rival school girl, it becomes even better. one can even consider a revolt within Bullworth for a shortwhile.
However, the Bully 2 should have multiple ending choices depending upon the deeds of Jimmy-i.e. If he helped someone, if he beat up some one this should have an effect on the game. If jimmy befriends a girl and cheats on her, it should also have some effect.. Secondly, the graphics needs to be improved significantly in the new version. The town could look little more real and so as the environment. Finally, there should be a easier saving option.