Michael Ledeen says Osama bin Laden is dead. He writes elsewhere on NRO today:
And, according to Iranians I trust, Osama bin Laden finally departed this world in mid-December. The al Qaeda leader died of kidney failure and was buried in Iran, where he had spent most of his time since the destruction of al Qaeda in Afghanistan. The Iranians who reported this note that this year’s message in conjunction with the Muslim Haj came from his number two, Ayman al-Zawahiri, for the first time.