I've read the book. He does an excellent job of showing that moderate Islam just can't win over militant Islam. A good read.
In the sense that Christianity had a reformation, and a bloody one at that, I believe Islam can only survive (as a peaceful faith that co-exists with other human faiths...) if it has a similar "reformation". It is a dichotomy that I - all at once - hope for and yet do not expect to happen. The hope springs from my optimism that those of us in the West... and even those silent voices within Islam - who truly want peace can win this.
The skepticism comes from my reading of the Old & New Testaments - nowhere do I find any indication that "the King of the South" will repent... in fact, it is quite the opposite. A case can be made that - in regards to the three great monotheistic faiths of the world, Judaism, Christianity & Islam - the Antichrist of the former two can be described as the "saviour" of the third (and vice-versa; the Islamic Anti-Mahdi fits the description of the Jewish Messiah/Christian Saviour as well).