The above posts all make great points. Democracy is indeed more than just a political system. Many of the countries in the East would struggle with the concepts of giving everyone a voice in how the country should be ran.
The same problems exist as in other countries that have long had autocratic rulers and populations with no experience in democracy. There are so many elements to a democratic system: a free press, independent judiciary, an election system that is open and fair, individual rights clearly specified in a constitution, etc. To transition from dictatorship at the same time as the people are educated in what freedom and democracy actually are and how to use it, as well as developing a new code of laws based on majority rule, forming political parties, and establishing a social contract with the people based on trust in the system is a long, complicated process with absolutely no guarantee of success. I would say Tunisia and Egypt have a better chance than Libya or Syria at completing this process.
There is a tendency for those of us who are products of Western culture to believe that it is superior to all others, including its political processes. It has only been in the past few years that World History has encompassed the entire world's cultures, not just Western civilization. My point: democracy is a western concept. It works well in the west because it evolved there and has become natural to us. Democracy is alien to other areas of the world; and I'm not sure we have the right, much less the obligation, to "introduce" democracy to them. It is as alien to many of these cultures as a theocracy would be for us. Human rights abuses to the contrary, I'm not sure democracy is a good fit for some areas of the world; and if that is the case, they should be allowed to develop their own institutions in ways that are comfortable for their culture.
When you think about it, a Democracy is not only a government, but a way of life. Those who are used to live in a democracy learn to live it, breath it, and become it. Like #1 stated, the countries that you mention have spent centuries living and breathing their way, with their idiosyncrasies, and their way of life. Just imagine if someone came to the U.S. to tell us that we should implement Socialism or Communism as our main type of government. Just imagine how hard that would be to do! It will not only interfere with our economy, but with our traditions, our ways of thinking, and even with the way we see our country as a nation. Hence, it would be nearly impossible to expect that a nation (complete with its culture, ethnicity, religion, etc) agrees to change everything they know about themselves just because someone else thinks that one form of government is more convenient to them than another.
I don't know enough about these places to know for sure what the chances are for democracy. However, I do think that I know why democracy is so hard to implement. The reason for that is that these countries (and many others in various parts of the world) have no real history and tradition of being democratic.
If you think about the US, our movement towards democracy is something along the lines of 900 years old. We, of course, got our system largely from England and they had been moving towards greater democracy since around the time of the Magna Carta. The move was very, very slow and gradual. The level of democracy we have is built upon the foundations laid by all those generations of English people (and then Americans).
Democracy is not just about institutions that can be created over night. Instead, it is about attitudes. It is about the attitude of accepting others as your equals. It is about the attitude of understanding that democracy is more important than whether your political party wins or loses this particular election. Because we have had centuries to develop these attitudes, we are able to have a successful democracy. These countries that you mention do not have that experience. They are just starting out, for the most part, on what will hopefully be their movement towards democracy.