Spengler argues that hopes for an Islamic 'Reformation' along the lines of the Protestant Reformation are in for a serious disappointment. Here's the reason: Whereas the Old and New Testaments are the Word of God as passed to Man, the Koran is THE Word of God as dictated to Mohammed by the archangel Gabriel. The difference appears small but is truly momentous. If the Koran is THE word of God, there is no interpretation involved and it cannot be changed.
None less than Pope Benedict XVI agrees:
And immediately the holy father, in his beautiful calm but clear way, said, well, there's a fundamental problem with that because, he said, in the Islamic tradition, God has given His word to Mohammed, but it's an eternal word. It's not Mohammed's word. It's there for eternity the way it is. There's no possibility of adapting it or interpreting it, whereas in Christianity, and Judaism, the dynamism's completely different, that God has worked through his creatures.
This isn't to say that a sea change in Islam isn't possible but it's much less likely than in the Judeo-Christian tradition. However the West needs to hope for and foment this change while preparing for a clash of civilizations.