"He said that the robes Osama was wearing were typical of clerics from a certain area of Iran."
I'm glad you posted that.
I posted that question awhile back asking what cleric
robes for Iran looked like.
Several ME-related forums had indicated he was now
attempting to and/or was considering himself an Islamic
cleric and 1 pointed to an Iranian muslim cleric.
Shortly after, I saw that UBL "the Mahdi" debate going
on on several boards.
His choice of Afghanistan as a base (rather than any other failed state, like Somalia or the Sudan) was an attempt to hook into some Mahdi prophecies, which refer to that region by some archaic Arabic name as the place where the Mahdi will arise.
Of course the jihadis have been considering him to be the Caliph for a while (which doesn't win friends or influence people in Iran or most of Iraq, since the Shi'ites regard the Caliphs as illegitimate usurpers).
Miniter was very specific this morning that this robe is from a certain area of Iran. As Callmejoe pointed out it's from the Mashad area of Iran.