I have not read the book, but I've read several reviews from various quarters, and while his attitude and exposition is more than a little bit over the top, there's a grain of truth that he's trying to expose.
The "atheistic fascism" that's grown more visible in recent years has come from the shift of most atheists from having to spend time justifying an atheistic worldview, to actively promoting the concept that religion is "evil" and must be eliminated if man is to move forward or even survive.
Its this hostility that makes it "fascist" or at least subject to parallels with the neo-con desire to subversively transform the world to align with their worldview.
As one review I read pointed out, some of his targets--like Richard Dawkins--are certainly strident, but unfair targets, but others like Sam Harris and Christopher Hitchens might well be (while you'll have to sit through an ad if you're not a subscriber, there's an
interesting interview with Chris Hedges in Salon.com this week).
As I've pointed out before on this general topic around here, attacking and demonizing religion is probably not going to prove to be a very effective tactic in promoting atheism, in fact, its probably going to be self-defeating. So while I think his delivery is obnoxious and nearly slanderous, I do agree at least in part with his message, even as someone who promotes atheism.
It really needs to be noted though that this kind of hostility actually is not as new as some would expect, its just gotten *popular*, that's all....
Whenever we read the obscene stories, the voluptuous debaucheries, the cruel and torturous executions, the unrelenting vindictiveness, with which more than half the bible is filled, it would seem more consistent that we called it the word of a demon than the Word of God. It is a history of wickedness that has served to corrupt and brutalize mankind,

Buffy