One more note... a few people have expressed concerns about the system, specifically around low volume contributors.
In my opinion, a poster with +5/-0 or even -1 is doing well. I really believe the key is to leave the system in place for an extended period to work the anomalies out of it and people will eventually get an appropriate rating. +5/-1 means a low traffic, valuable contributor. Higher numbers mean more contributions, and the rating values give a sense for the tone of those contributions. Over time, anyone who contributes will have high numbers, positive or negative, even if they are "low volume" contributors.
In the early days (I.E. right now), it's going to be very easy to skew those ratios one way or the other, but as time goes on, they'll "settle in" to the right values. For example it's easy to change the "tone" of a rating for a user who has just 5 votes. However when they have 20, or 100, a single vote will do nothing to change their "standing". It's only after a trend starts to develop in their rating that their style will become clear.
So in a nutshell, it's going to take a bit of time for the system to be useful, which is why I think we need to give the it fair shake before we call to shut it down.
Cheers
Mike