It had been looking to me like the Iranian opposition was running out of steam, but this seems to give some new life to their movement:
The most important group of religious leaders in Iran called the disputed presidential election and the new government illegitimate on Saturday, an act of defiance against the country’s supreme leader and the most public sign of a major split in the country’s clerical establishment.
A statement by the group, the Association of Researchers and Teachers of Qum, represents a significant, if so far symbolic, setback for the government and especially the authority of the supreme leader, Ayatollah Ali Khamenei, whose word is supposed to be final. The government has tried to paint the opposition and its top presidential candidate, Mir Hussein Moussavi, as criminals and traitors, a strategy that now becomes more difficult — if not impossible.
It seems difficult to maintain legitimacy while denying the will of the people in the name of theocracy when leading religious authorities are coming out against you. Not that pure logic is enough to defeat a dictatorship, but legitimacy does matter.