Actually, this is old news – dating from about June '06 – but it seems to have dropped off the radar since then, and the latest hearings about the OSP give it fresh timeliness. The Iranian Directorate is an office within the Pentagon, situated in the same offices as the OSP used, sharing some of the same personnel with the OSP (including the OSP’s director, Abram Shulsky; but the name of director of the ID remains a secret), and set up to . . . well . . . read these accounts:
Unlike (AFAIK) the OSP, the ID has a State Department counterpart, the Office of Iranian Affairs. (Actually, the distinction between the two is none too clear; they appear to use the same offices.)
Issue for debate: In the current political climate, when Congress obviously is going to look a lot more closely at “intelligence” reports than it has in the recent past, and it’s very clear we don’t have the resources for military action against Iran anyway*, is there any good reason for this agency to exist? What’s the point of it?!
*And yes, that includes an airstrike – because wargame simulations show there’s no way to prevent an airstrike from spinning into a general regional war.