I am between yes and no in this one.
It can surely help new users to identify who is usefull and who is a forum spammer but at the same time it gives a powerfull tool to anybody that has an oposite opinion than yours, to give bad feedback.
Not all of us think the same way, and not all of us understand exactly "why is this button for".
For some the "reputation" button means "I dont like this answer" or "I dont like this guy" and not "this is helpfull, ontopic or not".
So, I really don't know what to suggest here :-P
