First, as Timur Kuran and others have shown, the actual revolutionary potential of any society is very difficult to read in advance, and a rising revolutionary wave often depends on very particular preferences and information effects within society. Put differently, whether a genuine upheaval breaks out and gathers steam is a highly contingent process.
Second, Tunisia is an obvious warning sign to other Arab dictatorships, and they are bound to be especially vigilant in the months ahead, lest some sort of similar revolutionary wave begin to emerge. Third, Tunisia's experience may not look very attractive over the next few weeks or months, especially if the collapse of the government leads to widespread anarchy, violence and economic hardship. If that is the case, then restive populations elsewhere may be less inclined to challenge unpopular leaders, reasoning that "hey, our government sucks, but it's better than no government at all."
The direction other authoritarian governments take toward any incipient protest movements will be instructive. Ben Ali began to toss out concession after rapid concession before he ended up on the tarmac. Do the region's other autocrats think it was a case of too little too late and move to accommodation, or do they opt for more brutal suppression?
One large ripple: 3,000 Jordanians, inspired by events in Tunisia, took to the streets in Amman yesterday.