With the death of Muammar Gaddafi and his sons, the long generation of North African dictators comes to an end.
I think what made the time ripe for a successful revolt in Tunisia, Egypt, and Libya was that the nations that had put up with dictators since independence, were not willing to stomach the even more brutal and corrupt sons of the dictators as they threatened to come to power.
This is also, I think, why the time has not been as ripe in Yemen, Bahrain, or, saddest of all, Syria. The Syrians missed their moment when the current dictator succeeded his father. I wish all three nations well in replacing their tyrants. Yemen might pull it off still.
On the whole, though, I think the "Arab Spring" will turn out to be the "North African Spring" as the post-independence autocrats get replaced by a broader ruling group. This is still a great achievement. But democracy in the Arabian peninsula will probably have to wait another season.