The regime in Iran is far worse than Saddam, but the situation in Iran is far different. Iran has a long history of fighting for democracy. There are consistent pro-Democracy demonstrations in Iran - 70% of the population are under 30 - polls put the regimes support at about 15% and the younger generation are pro-American. A revolt works much better when dealing with Iran.
Then maybe what we need to do is weaken is infrastructure of the government to give the Iranian people a chance.