Essentially, this is a discussion for exploring the basic questions of social ethics (and perhaps a pinch of politics) from an atheistic worldview.
What is the 'utopia' (or maximal state of affairs, as expressed in the way society is constructed) that atheists (should) aim for? A wholesale affirmation of individual freedom? How much pain should be negated? Should religion be extinguished, or does it serve a purpose in an ideal society?
As if that weren't broad enough, another aspect of this worth exploring is the 'why' question. Why act in such a way to bring about the ideal society? Christians can claim the authoritarian command of a God for ethical action, but atheists can make no such appeal. Can reason itself provide enough of a ground? Empathy? Mutually beneficial selfishness?