I only managed to read three reviews of this before I felt compelled to add my own comments. Dawkins does not suggest that he is 100% correct, neither does he base his judgements on 'blind faith' as one reviewer here put it. The God Delusion is an excellent dissection of religious faith, a polemic which lays bare the often nonsensical and ridiculous beliefs held by religious people. Dawkins bases his ideas on sound scientific argument, on logic and, above all, on common sense.
The God Delusion is a wonderfully written piece, never becoming too technical or high brow so as to be beyond the grasp of us mere mortals, and given Dawkins' immense stature in the scientific community you'd be forgiven for expecting a book which only those in a similar field could hope to understand. I read this in an almost constant state of awe. Dawkins has somehow managed to put down in print things that, I now understand, I've been unconsciously thinking about for years but never given voice to. A happy agnostic two weeks ago, I am now an ecstatic atheist and I recommend this book to anyone who's ever expressed even the tiniest doubt that their religious beliefs might, after all, be poppycock.
If I had any complaints they would be thus: the book is obviously aimed at an American audience and I found this disappointing (that's my nationalism coming through!). There are also some instances of 'the Emporer's new clothes' about it, almost encouraging the ridicule of those with faith, which I don't believe was intentional but it did come through. Apart from that, this is probably the most important book I have ever read and I can't wait to read it again. First though, I'm reading Charles Darwin's Origin of Species!