"In reality, fiduciary duty means different things in different jurisdictions and in different contexts and, as a blanket statement of legal obligations, implies little more than a special relationship that has trust and confidence at its heart. Although fiduciaries have certain duties imposed on them by law, and may face tougher consequences if they breach those duties, the precise nature and extent of their duties can vary considerably. It is perhaps not surprising, therefore, that final guidance on the meaning of fiduciary duty issued this month by the [SEC] has revealed some disagreement among market participants."