THE DEMISE OF SECRET MARK is described by Bruce Chilton in "Unmasking a False Gospel" in the New York Sun. Excerpt:

A recent book by Stephen C. Carlson shows us how the basics of scholarship were eclipsed by sensationalism on the left, compounded by willful dismissal on the right, and why "Secret Mark" needs to be seen as a fraud. In "The Gospel Hoax: Morton Smith's Invention of Secret Mark" (Baylor University Press, 151 pages, $24.95), Mr. Carlson, a lawyer, argues his case as if in a civil proceeding, meeting the test of proof by preponderance of evidence, rather than beyond a reasonable doubt. He has mastered his brief impressively, and although in my view he does not quite prove that Smith was a forger, he does demonstrate - within the limits of certainty that incomplete evidence involves - that "Secret Mark" is someone's forgery, and that Smith, who died in 1991, was the likely culprit.

He'a also pretty hard on modern "neo-Gnostics":

Publicity and naïveté have encouraged the rise of a form of neo-Gnosticism, a fashion greatly encouraged by recent discoveries and alleged discoveries. In embracing these ancient sources, the neo-Gnostics are unlike their ancient counterparts. They want to embrace the earth, not subjugate it; they don't wish to be elitist. Above all, they want to insist on the gender-equality of women with men. You need to cherry-pick Gnostic sources, and ignore a great deal of what they say, to make that picture work as an account of the Nag Hammadi library. Neo-Gnostics do just that, and falsify history. Many ancient Gnostics were openly anti-Semitic, taught that the physical world was the hopelessly corrupt product of a false god, and insisted that only the predestined elect could know the divine truth. These are persistent tendencies, rather than a set of precise ideas that all Gnostics repeated, but they are facts that can't be denied.

One can make the same sort of criticisms of a lot of religions, and I'd rather see them improve on Nag Hammadi Gnosticism than the alternative. But that's just me. The final paragraph has some searching criticism of scholars:

No literature has suffered more from this problem than that of the second century of Christianity. In the case of "the Secret Gospel," a modern researcher ( Morton Smith himself, or someone whose forgery duped Smith) has made up a Gnostic document up in the attempt to manipulate scholarly discussion and public perception. The fact that this attempt succeeded for so long stands as an indictment of American scholarship, which prides itself on skepticism in regard to the canonical Gospels, but then turns credulous, and even neo-Gnostic, when non-canonical texts are concerned.

UPDATE (27 October): To clarify, regarding the neo-Gnostics: Many, perhaps most, religions can be accused of misconstruing and selectively reading their own scriptures to suit later agendas. Some go as far as falsifying history (for example, Christian fundamentalist creationists and Muslims who deny that a Jewish Temple stood on the Temple Mount in Jerusalem). If people today want to be Gnostics (and it's not for me to tell them whether they should be or shouldn't), I would rather they be Gnostics who support women's rights and the prudent use of the earth's resources and who aren't anti-Semitic. If any of that is untrue to ancient Gnostic scriptures or doctrines, so be it. (But if they want to claim that these are the actual values of ancient Gnostics, I will, as usual, call them on any historical inaccuracies.)

UPDATE: Loren Rosson takes a somewhat different view over at The Busybody. And (via a comment by Stephen Carlson in the same post) a neo-Gnostic responds to Chilton here.

ANOTHER UPDATE: More from Loren here.