@cicerone imposter,
To bring your point closer to home, consider the cousins Sam and John Adams.
Sam was a revolutionary. He was great at overthrowing, but not so great at rebuilding.
His cousin John, on the other hand...
We need both, because we will seldom get them within the same single person.
The potential dissapointment of the so-called "Arab Spring," is just this: Taking something down doesn't assure it will be rebuilt according to the revolutionaries ideals or according to what is just simply right.
I'm not ready to jump on a band-wagon of anti-Muslim Brotherhood critics as respects Egypt, but there is reason to be concerned.
There are certainly plenty of signs that suggest that the MB will not be able to bide their time and their pledges to not become prominently involved with the rebuilding of the Egyptian government are hollow...at best.
When the time comes for elections in Egypt, there will be a MB candidate...even though they said, during the upheaval, that they would not field one.
They have a very good understanding of the Western Liberal audience to which they are willing to play.
We all rejoice when the oppressed rise up against their oppressors, but only the most romantic of us assume that the oppressed will, perforce, deliver a government significantly better that what they defeated.