This archive page for the radio program Unbelievable? has links to a well-moderated debate between Peter Williams and Bart Ehrman over Ehrman’s recent book Misquoting Jesus.
Williams gives one of the better responses to Ehrman I have heard: in the short time he is given, he works at exposing Ehrman’s central, overused rhetorical strategy. Rather than getting mired down in specific textual questions (especially those which Ehrman worries in book after book), he instead points out Ehrman’s habit of making the worst of the evidence before him (evidence which, even Ehrman admits, really can’t do too much to threaten Christian doctrines), and his tendency (in line with this habit) to cast doubt over our ability to know whether any part of Scripture is trustworthy because there are serious questions over some passages.
Ehrman is a prime example of someone whose god (in his case a Bible with perfect provenance, with no disputed readings), when knocked down, left him with nothing. His popular work is little more than his hoping to bring down this false god for everyone else — again with nothing held out to take its place. It seems that Ehrman was given the Bible without Christ; of course he finds nothing trustworthy in Scripture. He does not have the Key of David, Christ himself. He studies the Scriptures without knowing who to look for in them! Here again is an example of someone destroyed by the false promises of fundamentalism (and its false understanding of inerrancy; see here, for a simple critique of it) — and a lesson as to the necessity of preaching Christ, Christ crucified and raised from the dead for your sake and mine.
Followup: A review by William Willimon, skewering Ehrman’s most recent book, God’s Problem. Thanks, BHT!