That token breaks the very anonymity in the first place. The very essence of anonymity is having no reputation, no information whatsoever.
No reputation or information is a recipe for meaninglessness; as a reader I have neither the time nor the tools to fully evaluate every statement ever made to me; I must use heuristics to aid my reading (e.g. I will almost certainly ignore anyone who claims the moon landings were hoaxes; it's not worth my time to investigate his claims).
I'm actually very excited by the idea of anonymous reputation, as it could enable all sorts of the things needed to have a well-run global network without enabling physical assaults on persons.
For trading pseudo-anon there is already this reputation system which has worked well http://bitcoin-otc.com/trust.php