Predicting whether the outpourings of popular disaffection sweeping the Arab world will continue to spread or result in real revolutionary change is a mug's game. There's been a change in tone among regional experts from, "Not a chance," to, "Not likely, but this feels different." But this kind of phenomenon is by its nature unpredictable, otherwise tyrants and despots would either head it off at the pass or know exactly when to pack their bags and head for the border.
That said, everyone knew that in the long term, these regimes were not sustainable. What is now becoming obvious is the degree to which the region resembles a thin crust of dry earth slapped down over a flowing current of molten lava. For now, that lava is springing up here and there in spots that still might be plugged up. But I don't think anyone can observe what's happening now and believe that the regional status quo as it has existed over the past 25 years is long for this world. Uprisings can be repressed, but the aspirations they represent cannot be extinguished. So what we're seeing today is the first glimpse of what the region will look like after the inevitable changing of the guard.
For now, that is being framed as: a democratic Arab world = an Islamist Arab world = an anti-American Arab world. I'd argue that we still don't know if what comes next will be either democratic or Islamist. But it seems like a safe bet that it will be anti-American.