As a fairly unobservant atheist (and fairly unobservant Jew), I have to respond to this post. It's one thing to have reasons to be an atheist (I do) and a Jew (I do), another thing altogether to adopt some level of "observance." You can have good reasons to be an atheist, and other good reasons not to be observant--i.e. not to focus on it, talk about it a lot, promote it. Maybe you find it obvious and uninteresting that there's no deity (the attitude, I think, of many atheist philosophers). Maybe you think there's no god, but you don't mind that others believe differently--since you think belief can have both good and bad effects. Maybe you have other goals that would be thwarted, if you got on the "religion, baaaad" bandwagon. For example, maybe what really matters to you is the environment, or poverty, or animals, and you think you can advance progress in those areas if you reach out non-divisively to both religious and non-religious people.
Finally, it's a very bad idea to use the term "anti-atheist" for unobservant atheists who criticize "the new atheists." It echoes "anti-semite" and thus misleads badly. There are people who really do despise atheists in the way that anti-semites despise Jews. Unfortunately, I come into contact with such people, and they upset me. Critics of the new atheists (like Chris Mooney, like me once in a while) are nothing like them. The critics have reasoned complaints about a subset of atheists; they don't despise or fear or denigrate atheists just for being atheists. They're not "anti-atheists." So much for that.