i think this guy has some valid points, but i don't agree with all of his arguments.
firstly, people have used religion and 'god' as reasons for their violence and stupidity on numerous occasions right throughout history. from the ancient romans, to george bush who reckons he is acting on behalf of god when he went to the middle east. people use religion as an excuse for far too long, and this is an undeniable fact.
he says and i quote 'Religion, he argues is superstition. It is the enemy of rational thought, the ever-present threat to civilisation, the fuel of war, the bastion of bigotry, the rulebook for systematic human rights abuse, the virus with which parents infect their children. In the home, and in church schools.' do you not think he's making some sense? why are children christian just because their parents are?
however, i do think religion or 'god' act only as a symbol. a symbol which people hope that their good deeds will not go unnoticed; that their wishes be heard and granted; that in their darkest hours, someone or something is watching and provide them with comfort and sympathy; that when they pass away, their 'soul' can enjoy eternal happiness. psychologically, i think this can be a positive for many people, and almost an integral part of their lives for some other.
in regard to the so called 'sins', i strongly believe those responsible have the final say in what they do - they alone are responsible for their actions. sure, religion can be more or less an influence, but what is influence if the will is strong enough to prevent the it from clouding the judgement?
all in all, dawkins has some valid points, but in the end, people choose their own actions.