Bullshit. They've had a common enemy for sixty years and it hasn't enabled them to overcome their differences. Different nations are different. Turkey is completely unique. Look at their system of government, it's secular, and has been for years, and they got there on their own. The Arab Spring protesters were very mixed, but largely Islamist. These protesters are largely secular. Look at Iran. I'd say it's much more likely they secularize their government in the next ten years than any kind of substantial caliphate spring into existence.
Having a caliphate was one thing when you had one rich city-state dominating a vast poor expanse. It's a very different story when you have a dozen rich countries, each with their own tiny army, each with their own couple ethnicities, each one wanting to pronounce everything differently and quite unable to agree on who succeeded Mohammed.
It would be really convenient to be able to paint all our troubles with a single brush and a single color of paint, but the truth is much more complex and interesting.