Gamasutra has an article on the dubious practices of gold selling and power leveling services.

Overall, the battle between leveling companies and game producers will be long-lasting. At present, there is no explicit legal rule to claim whether the service is allowed or not regarding - therefore, WoW power-leveling needs a long period to be completely mature. Everyone is waiting to see what happens.

Definitely an intereresting take from the other side of the fence.