Personally, I'm against it. I think it's wrong to decide someone's future for them. A lot of the time, the person they end up marrying could be someone they hate. They should be allowed to choose who they spend the rest of their life with, and who they have kids with.
I have a friend called Abera, who is Sri Lankan (I think), and she's been "engaged" since she was five. She really doesn't like this guy, but there's nothing she could do about it. I feel bad for her.