I am aware of two other recently published responses to Sam Harris.
Dr. R.C. Metcalfe has written Letter to a Christian Nation: Counterpoint,
which was published last month.
Douglas Wilson, the famous originator of Classical Christian education, has written Letter from a Christian Citizen,
which is being published this month.
All three of us respond to Sam Harris with vigor and intellectual rigor.
It's interesting to note that though we all debunk his approach, we all seem to be taking him to task in different areas. I'm thinking Harpeth River Press may want to combine all three books into a Response to Sam Harris sampler !
On first blush, you might think that this removes any "first actor advantage" that Letter to an Atheist
On the contrary, the existence and success of both these other books will do nothing but grow the market and awareness of the vigorous Christian response to Mr. Harris.