Well, you can add and subtract reputation by using the scales, which is what dave thought was meant with the +1 -1 discussion.

Personally I am of the opinion that by participating in the community, people will soon enough find out who is who. And if people can't be bothered to spend enough time here....... I am not going to write it out, but I think you get my point

But regardless. It is here, and we will see how it will be used.