The new reference encyclopedia, Books and Beyond: The Greenwood Encyclopedia of Literary Genres is now available (see link below). It includes an entry written by yours truly on "Christian Fiction."
The essay contains a definition of the genre, a history of its development, common themes, current issues, and selected authors who participate in it. I do manage to cite M. Leary's "How Should we then Review?" essay as well as E.J. Park's essay about commercialization (in Christianity Today) and my own essay in The Matthew's House Project on evangelical pornography).
While the price of a three volume set of reference encyclopedias would probably be prohibitive for individual buyers, I do recommend the essay if you have access to a reference library and (if you work at or in conjunction with an academic institution) think it would make a good addition to a school reference library that could be recommended to your acquisitions department.