Sam Harris recently spoke to the Atheist Alliance in which he argued that using the term "atheist" is a mistake.
I think that “atheist” is a term that we do not need, in the same way that we don’t need a word for someone who rejects astrology. We simply do not call people “non-astrologers.” All we need are words like “reason” and “evidence” and “common sense” and “bullshit” to put astrologers in their place, and so it could be with religion.
The problem with this line of reasoning, as I see it, is that using the words Harris lists do not, as he says, "put astrologers in their place." An astrologer, like a theist, is not going to reject -- or even question -- their beliefs just because someone calls bullshit on them. The other problem is that astrology, unlike religion, does not hold any real sway in public discourse. Astrologers are not trying to teach children bad science in classrooms, for example. The astrology column in the newspaper is usually next to the comics; it does not comprise an entire "Faith & Values"-type section unto itself masquerading as real news or legitimate advice.
Like Harris, I would dearly love for religion to be on par with astrology some day, and for those who believe in the imaginary creator in the sky to be regarded the same as those who turn to the zodiac for guidance.
But, we are clearly not yet at that point -- as Harris observes, "240 million [Americans] apparently believe that Jesus will return someday and orchestrate the end of the world with his magic powers."
In his call for atheists to not use any label at all -- not "secularist," "rationalist," or the admittedly cringe-worthy "bright" -- Harris argues that "accepting a label, particularly the label of 'atheist,' ... seems to me that we are consenting to be viewed as a cranky sub-culture."
And that's as may be -- I do feel cranky at how delusional the broader culture is. This term I use to describe myself positions me within the culture in opposition to views and opinions that I believe have no merit and no business being seriously discussed. And it helps me identify my allies in that struggle. If Sam Harris, or his publishers, had never used the term "atheist" to describe him and his writing, I probably never would have found him, and I doubt he'd have been asked to speak at the Atheist Alliance.
Admittedly, use of the term "atheist" (or any similar term, as per Harris' point) may serve to repel those who are not likeminded. But how receptive to rational arguments would they be even if it were served up without a charged and overdetermined label?
To me, therefore, the term is undoubtedly problematic but remains more useful than not.
UPDATE: Upon review, I see that PZ Meyers has a similar, and probably more insightful, reaction up at Pharyngula.