All this talk about whether democracy in Egypt will be a good thing or a bad thing just goes to show how misunderstood the word democracy is. Democracy refers not so much to elections but to liberalism in the general sense of the word.
If Egyptians elect the Muslim Brotherhood in a free and fair election, and the Muslim Brotherhood then rigs or even cancels every election that follows, Egypt will not be in any way shape or form a democracy. It will be a dictatorship that happened to have an election.
Mature liberal democracies have checks and balances, the separation of powers, equal rights for minorities, restrictions on the power and reach of the victors, and guarantees that those who lose will not be persecuted.
The Arab world doesn’t need a one-time plebiscite on whom the next tyrant is going to be. It needs liberalism. Egypt won’t get it from the Muslim Brotherhood, nor was Egypt ever going to get it from Hosni Mubarak.
I have no idea if Egypt will get it any time soon. Unfortunately, the profoundly illiberal Muslim Brotherhood is a powerful force to be reckoned with. Something like the Iranian Revolution in 1979 may well be replicated, but it isn’t the only possible outcome. Indonesia managed to overthrow Suharto without bringing a Southeast Asian Khomeini to power, and Albanians face no threat of an Islamist takeover even decades after removing Enver Hoxha.