Given the way the hard-core Muslims talk, I would think that their plan (i.e., Iran) is to get the nukes, take out Tel Aviv, New York, Washington, whatever, and sit back and let Allah sort it out. It's kind of built in to their religion.
That said, the people of Iran as a whole are reasonable and just looking to live their own lives, just like us, and if there was enough of a popular uprising, supported by the West, maybe Iran's mullahs could be fettered and the country be allowed to rejoin the modern world. If only... oh, wait, that happened a few years ago and we sat on our hands. Oh, well.