What is not exactly clear, right now.
The rumor of the day ("Supreme Leader" Khamenei in a coma or dead) is one guess.
Whatever is happening is starting to be seen by its effect on the public in Iran. The bazaars are said to be closed today (Thursday) and that they will remain closed Friday (that is itself not too surprising; the day of the public prayer meetings).
There may be a succession crisis brewing. There may also be a move by the Ahmadinejad government to lock in its place in power. It could just be a moment of instability that will bring the "Greens" (the "Where is my vote?" Opposition) back out into the streets.
Keep an eye on this. Something is happening.
Update 15.Oct, early
Nothing official out yet... but no retractions from the unofficial sources either.
Okay... we have reports of a denial. The Iranian Embassy in Armenia gave a news site there a vigorous denial and made accusations of "slander".
Not exactly convincing, but it is a first.