Darrell Bock begins his critique of Ehrman's latest book. As Bock identifies here, Ehrman has a modus operandi that, once you recognize it, basically deciphers the flaws in his books. But that M.O. creates a lot of hype and sells a lot of books.
One has to wonder when an author admits to providing nothing new in a book what the motive is for writing. Informing? Apparently not. Crusading? Perhaps. But to leave the criticism on this point would be to ignore the case Ehrman tries to make. The conservative writers Erhman apparently wishes to challenge (and mostly ignore) have engaged on all the "non-new" points Ehrman makes, even highlighting themselves the "human" side of the Bible's production. But partly by caricature and partly by setting rules where God cannot be invoked in a historical discussion, Ehrman proceeds. God is not even able to be brought into the possibility of an interpretive spiral, because "miracles are not impossible," just very much unlikely and a least likely explanation (read a "next to impossible" category). I think what is most bothersome in this book is the way it sets up discussions, pursues a topic for several pages, often noting the point is not as devastating as the impression given (usually with a sentence that qualifies things so the author has cover) and then continues to launch in a direction that implies more than the evidence really gives, leaving a greater impression about what is said than the author claims in the qualification.
Bock responds to some of the specifics claims in Ehrman's book, so read the rest.