What do you mean the transition cannot happen too fast? When Iran threw out the Shah they ended up with a progressive democracy with the interests of the people of Iran at heart. It was after America interfered and reinstated the unpopular Shah that the Islamic revolution occured. So unless America decieds to organise a coup against any democratic government that Egypt gets, this will end up nothing like Iran.
"If an injury must be done to a man, it should be so severe that his vengeance need not be feared" - Niccolo Macchiavelli