The official line (CBS News) is basically that we expect that Iran recognizes that
"the world is watching... I want to repeat it that we stand with those who would look to peaceful resolution of conflict, and we believe that the voices of people have to be heard, that that's a universal value that the American people stand for and this administration stands for.
"But the last point I want to make on this - this is not an issue of the United States or the West versus Iran. This is an issue of the Iranian people. The fact that they are on the streets under pretty severe duress, at great risk to themselves, is a sign that there's something in that society that wants to open up.
So the US is emphatically and conspicuously not taking sides.
On the other hand, by late 2007, Congress had agreed to fund a major escalation of covert operations against Iran (last year, I'd made a quick note about these operations). These operations
"are designed to destabilize the country’s religious leadership. The covert activities involve support of the minority Ahwazi Arab and Baluchi groups and other dissident organizations
Indeed, these minority groups are involved in the protests.
Granted, these covert operations were initiated under a very different administration than the Obama administration; but a Counterpunch article by Paul C. Roberts, assistant secretary of the treasury in the Reagan administration, seems to put these doubts to rest.