Robert Connor graciously passed along to me a draft of his forthcoming book, The "Secret" Gospel of Mark: Morton Smith, Clement of Alexandria, and Four Decades of Academic Burlesque, to be published by Mandrake of Oxford. Mandrake's web page provides the following abstract:
While cataloging material in the library of the monastery of Mar Saba in 1958, Morton Smith discovered a quotation from a letter of Clement of Alexandria copied in the end pages of a 17th century collection of the letters of Ignatius. After more than a decade of collaborative analysis of the find, Smith published his conclusions in 1973, setting off a firestorm of controversy in the New Testament studies guild.
In 1975, a Jesuit scholar, Quentin Quesnell, claimed the letter had been forged and implied that Smith was the forger, moving the focus of debate off the text itself and onto Smith. Since then the pages containing the letter have been removed from the book and possibly destroyed, while Catholic and evangelical writers, none of whom have ever seen the pages in question, continue to claim that Smith forged the letter.
Following his death in 1991, accusations against Smith took on a considerably more personal tone, highlighting his alleged homosexuality and by implication his dishonesty and moral perversity. Although the question of authenticity remains unresolved, the controversy has opened a window on the intellectually corrupt nature of apologetic New Testament studies, a subject of greater importance than the authenticity of early Christian texts.
Connor's small book spends more time criticizing hoax/forgery theorists (particularly Peter Jeffery) than analyzing the text; however, he does present a theory for why the Secret Mark pericopae were removed from the text to form what is now canonical Mark. I won't spoil the book here but if you want to get a good sense of Connor's arguments, listen to an interview with the author on the internet radio show Aeon Byte (on Youtube HERE), hosted by Miguel Connor (no relation). The interview begins around the 15 minute mark.