The first reports of the protests from the BBC's Persian "service" said that the first protests were organised by the clerical faction of the ruling class within which there are constant tensions. The clerics, and behind them the Revolutionary Guard, were warned by the government that they were playing with fire and the protests have spread rapidly.
Probably related to this is the fact that there were already extensively organised marches and patriotic celebrations today to commemorate the anniversy of the 2009 "Green Movement" protesting against the fixed election result of an Ahmadinejad win. There were elements of the "Arab Spring" to the whole movement but it was overwhelming patriotic and part of the faction fight of the Iranian bourgeoisie. The protests were put down with the most brutal force by the regime's secret service along with thousands of arrests and many executions. There were also certain imperialist elements to the protest movement with actions and manipulations from the US, Britain and Israel.
The workers stayed away from the Green Movement and its protests. The unions didn't get involved because there was no enthusiasm from the workers. In the following year,2010, there was a number of strikes and walkouts in Iran some apparantly unofficial. They broke out in the auto, sugar, textile, metal and transportation industries.
It's much too early to give an inidication of the strength of these protests but they appear to have started off from a faction fight within the bourgeoisie but there has been a great deal of anger simmering in the general population and in the working class in Iran.