Given this history and the assumptions the Obama administration has followed until now, this is interesting:
The Obama administration is increasingly questioning the long-term stability of Tehran's government and moving to find ways to support Iran's opposition "Green Movement," said senior U.S. officials.
It would be too much to say we are shifting away from assuming the Iranian government is firmly in control (and so we must negotiate with them over nukes) to assuming the opposition is capable of overthrowing the mullahs.
But it would be safe to say that we are now unsure of which way the winds might blow.