Although I have a number of Iranian friends from my time in Central Asia and Ukraine, they are mostly "liberal" in the sense that they are opposed to the clerical rule in Iran. Indeed, they call themselves Persian. So, I have no great knowledge of the socio-political structure of the country as a whole. However, reading the reports on the election and the aftermath, particularly the arrest of over 100 opposition leaders yesterday, one can't help but conclude that the margin of victory was fraudulent, if not the election itself.
One point that appears to repeat itself is that the rural vote put Ahmadinejad over the top. The huge margin seems to make this improbable as it would require a major shift in the urban vote as well.
Juan Cole has the best analysis at this time about the election results. As the weeks pass more information will appear. In the meantime, it seems that Israel will likely take this as an opportunity to push its aggressive stance against Iran - although attacking Iran is off the table as it would require US consent. I suspect as well that US policy will remain unchanged since Ahmadinejad has been president for the past four years and will be there for the next four. That's the fact on the ground that is not going to change, so US and EU policy should remain in place.
Whether the damaged credibility of the Iranian government if the belief that the election was stolen weakens its ability to deal with the outside world, including Pakistan and Saudi Arabia, not to mention the EU and the US, will be interesting to watch. President Ahmadinejad may need to dial down his rhetoric - which would be welcome in and of itself.