Like clockwork! I started a thread a couple of weeks ago about Egypt going down the same path as Iran... The only nice thing about these Islamists is that they're not very bright, and predictable as hell which means people will eventually catch on (like they did with the church in Europe) and not go down the same path again. Although I have not seen any references to Iran from any political figures in Egypt, I am certain the opposition is not oblivious to the situation.
For one, the military held on to power for a while and to some extent has some control even now (i.e. they followed more in the footsteps of Turkey). Another thing the Egyptians have going for them, which we didn't in the late 70's is the internet and how fast information can spread - it's much harder to keep people in the dark now about events than it was 35 years ago. There are three other important things to consider as well:
1 - Tourism: The majority of Egypt's GDP comes from this segment and the majority of Egyptians realize this. As the Salafi dude from Alexandria showed during the elections, by wanting to tear down the pyramids as the symbols of polytheism, Islamism and tourism just don't go together. Do what the IR did and ban alcohol and Sharm El-Sheikh will be a ghost town. Force people to wear "manto" and "roosari" and no tourist is going to brave 40°C temperatures to see the pyramids. The Egyptians can not afford to lost their tourist dollars and don't have the luxury of relying on their oil revenue like we did.
2 - US Aid: It's a huge some of money and although Islamists will eventually say f.. the US, like they're doing in Iran now, despite how much help they received from the US both for the Iranian revolution and the Egyptian one, Egypt's economy is at the brink, not like the situation in Iran in 79. Even the loos of that aid will push them over the edge.
3 - The IMF load: Interestingly enough, this seems to be their only saving grace at the moment. Mursi just told the Egyptians a few hours ago they have to pay higher taxes. It's one of the pre-conditions for the IMF loan to be released and it was expected next week. Within 2 hours, he had to retract that statement, the IMF delayed its release of the money into January and with foreign reserves at half of what they were when the revolution started, any more of this type of instability and uncertainty is eroding away at any gains the Islamists have made.
What these Islamists don't understand and never will is that despite being democratically elected, the constitution of a country has nothing to do with democracy - it can NOT be the will of the majority over the minority when its sole purpose is to be as inclusive as possible and to protect the rights of the minorities. As such, constitutions (including a future Iranian one) should be written by a group that represents every sector of society and that representation can not exceed the representation of any other group. And the decision on the final text has to be unanimous - that's the only way that you'll prevent one particular group from forcing its views on the society as a whole. Yes, Islamists can be represented, but every one Islamist, there has to be a secularist, a Christian, a Jew, etc., etc.