Almost every media report on uprisings in Arab countries includes an obligatory discussion of whether Islamic extremists will take over. This is prompted by memories of what happened in the Iranian Revolution of 1979 and under the Taliban in Afghanistan - neither of them Arab countries. However, Iran is overwhelmingly Shia, and what happened in Afghanistan was conquest, not popular revolution, helped by the West's earlier aid to the mujahidin (including bin Laden).
There is good reason to suppose that Egypt will not be taken over by anything resembling the regimes in Iran or Afghanistan. The great majority of Egyptians - like the majority of Muslims in the world, follow Sunni Islam, which arose out of events in the 7th century C.E. A civil war had sprung up between the Party (the Shia) of Ali, who believed that only he and his descendants had the right to head the Muslim State, and the majority, who said it was better for Muslims to tolerate a bad ruler than to fight each other. Sunni Islam developed into a broad and tolerant civilization, with competition between various schools of thought and practice. The Shia split into rival movements following different descendants of Ali, fighting against each other as often as against Sunnis.
The tolerant Sunni tradition continued until the 20th century, when an extremist faction, the Wahhabis, began to make inroads. This was a utopian revivalist movement that had been confined to the Arabian desert. Their fortunes changed when the collapse of Ottoman power and the destruction of the Hejaz Railway by Lawrence allowed them to take control of the Holy Cities of Mecca and Medina with consequent rise in prestige. At the same time, their Saudi Kingdom came into possession of fabulous oil wealth, enabling them to open Wahhabi schools in many countries and to flood the Muslim world with literature and now DVDs advocating a militant and intolerant view. The evidence is that, although they have excited a fanatical minority, the majority of Sunni Muslims are loyal to their open-minded and tolerant traditions. I do not believe that a democratically chosen government in any Sunni country would be dominated by Wahhabis.