The best thing the US could do now in Iran is nothing. Well they should question the legitimacy of the election. The people of Iran are fed up...
I disagree with this media-driven line.
The next events are wholly, easily and entirely, predictable:
1) The Supreme (asshole) Leader calls for a review taking 1-2 weeks (which the turd did), and this is done to placate the masses so that they go back to their merry little lives, and stop the protests.
2) during this time, many more leaders of the demonstrations will be arrested/executed/ to be never heard from again, and it will give time for the RG/Basij to tighten its grip on the capital and other cities so as to prevent any demonstrations in the coming weeks.
3) after 10 days where the protestors cool off, the mullahs will of course declare Ahmadinejad the winner after their "thorough" review, which is certified by a pliant, useful group of idiots they've made use of, either from allied nations like Libya, Sudan, etc. on the UN Human Rights Council, or useful idiots like J Carter. This will ensure the status quo, and re-instate the Ahmadinijad for another 4 years.
4) all attempts at resurrecting the protests are met with brutal force well beyond what has been seen in the last few days, with the vast majority of internet service eliminated and most foreign journalists expelled for the time being.
5) The false scholars will tighten their grip on power to ensure a similar situation does not re-occur, and they will arbitrarily, unilaterally change the constitution to ensure it.
6) all future efforts to weaken the regime's hold on power will be met with ferocious violence, and will compel large numbers of educated, middle class iranians to emigrate, precisely following the methods of Hamas in Gaza and Fatah in the West Bank - both of whom have conducted these actions for the last 10-20 years.
By removing the educated, and retaining only the poor and the stupid (i.e., religious), they can more easily sway a pliant, clueless public into whatever myths they manufacture, of external enemies/boogeymen at will.
The West will be facing a more radical, violent and tempermental regime that will increase its thrust of power utilizing terrorism throughout the middle east, and perhaps beyond - a regime that if it hasn't already done so, will attain nuclear weapons active capability within 12 months.