i am against it, I think kids should be taught to deal with their anger in a responsible manner, i.e. not assaulting and battering someone. something that comes with serious consequences, also, you never know if you are going to kill someone in a fight, people have died from a single punch.
at my schools we had peer mediation and it worked pretty good; you sit down wtih the person youre beefing with and you have two people your age there, theres no authority figures there to judge you. once you both spill it all out most of the time you both realize how ridiculous it all was to begin with. in more serious instances parents from both sides could be brought in to help. for this to work though the mediators have to really be mature and groomed to do this and not make the problem worse or start gossip. but my schools were good at weeding those people out and getting rid of them as mediators.
any other instance where this wouldnt work was mostly just stupid parents fault their kid was a dumbass to begin wtih. some things just wont work with those real loser lost cause types. in those instances yeah why not, let them both duke it out then expel them from school afterwards