The December 25 release of Guy Ritchie's new movie, starring Robert Downey Jr. and Jude Law as the Baker Street duo, makes this an appropriate time to speculate whether the film will be the catalyst for another spike in the publication of new Sherlock Holmes books, the first in more than three decades.

In 1974, PW ran a prescient article, “The Case of the Baker Street Boom,” which identified the coming revival of publishers' interest in Sherlock Holmes that marked the last half of the '70s, a month before the release of Nicholas Meyer's groundbreaking pastiche, The Seven-Per-Cent Solution. The so-called boom is commonly attributed to the confluence of Meyer's book's bestseller status and a successful Broadway revival of William Gillette's 1899 play, Sherlock Holmes. But did it result simply from the success of the pastiche and the play, or was there something going on beneath the surface that made the U.S. under Jimmy Carter fertile ground for a proliferation of new stories about the world's most famous detective?

Otto Penzler, owner of Manhattan's Mysterious Bookshop and genre expert, subscribes to Occam's razor on the topic—simply that after the huge sales of Meyer's book, publishers just “jumped on the bandwagon.” If Penzler is right, then the box office take of Ritchie's movie will dictate the receptiveness of publishers to sharing recently discovered lost manuscripts of Dr. Watson with the reading public.

There are alternative explanations. Steve Hockensmith, author of The Crack in the Lens (Minotaur, July 2009) and three other hilarious western whodunits featuring cowboy brothers who are inspired by reading Doyle's original stories, believes that the “huge wave of nostalgia” sweeping the country in the wake of the political turmoil of the '60s and early '70s made the timing perfect for a renewal of interest in Holmes. British author Peter Lovesey and Jon Lellenberg, the U.S. agent for the Conan Doyle estate and co-editor of seven anthologies of pastiches, both attribute the boom to a hunger for new stories; the number of new Holmes adventures had been limited by the hostile attitude toward them by Conan Doyle's son Adrian, who controlled the estate up until his death in 1970. His sister, Jean, who succeeded him, took a different position.

If these hypotheses are valid, it's much trickier to predict. Escaping to the foggy streets of a London where it's always 1895 hasn't been mainstream for a while; there's a reason Hollywood took a decadeslong break from putting Holmes up on the big screen, and why the new film, emphasizing action, is not meant to be confused with previous adaptations. And there's no shortage of pastiches to read; Philip K. Jones maintains a database of more than 8,000.

If the near future resembles the recent past and is not much affected by the movie's release, then readers can anticipate more of what Penzler terms “genre bending.” By his estimate “more than half of recent published works put Holmes in conflict with vampires, werewolves, supervillains, and in futuristic settings.” There's also been an increase in Holmes comics, most notably the graphic novel The Trial of Sherlock Holmes (Dynamic Forces, Nov. 2009), coauthored by Alan Moore's daughter, Leah. And the anthologies Lellenberg co-edits consist solely of works by established mystery writers; in the past, those with characters of their own were less likely to switch gears to the authoring of pastiches.

Perhaps the most significant trend has been books that, as Holmes expert Peter Blau puts it, “enter the world of Sherlock Holmes through different doors,” such as works by Laurie R. King, David Pirie, and Hockensmith that are not imitations of Doyle but are inspired by his characters and his imaginative storytelling. Pirie, for example, imagines Doyle himself serving as Watson to Dr. Joseph Bell, the real-life model for Holmes, most recently in The Dark Water (Pegasus, 2007).

Fans of the originals who don't want the characters tampered with or made over do have some basis for hope; there have continued to be high-quality efforts, most notably Denis Smith's almost unparalleled series of short stories, most collected in the four-volume Chronicles of Sherlock Holmes (Calabash, 2000). More recently, there's Lyndsay Faye's superb Dust and Shadow (Simon & Schuster, Apr. 2009), a compelling and convincing account of Holmes's tracking of Jack the Ripper authorized by the Conan Doyle estate, and Donald Thomas's series of novellas, including Sherlock Holmes and the King's Evil (Pegasus, May 2009). Faye proved, despite the number of previous books with similar themes, that a gifted writer can revisit familiar ground and come up with something both new and notable, thereby prevailing over the considerable challenge of the pastiche. As she says, “You can only win by getting Holmes and Watson spot-on while simultaneously tackling them in a way that's new enough to be worth reading.”

Faye herself contrasts the current approach of pastiche writers with that predominant in the '70s. Back then, “it occurred to authors and filmmakers that Holmes must have possessed an altogether singular psychological profile, and they no longer felt restrained in exposing its secret nooks and crannies.” Today, she sees “a return to the mysterious in the character of Holmes himself; we've returned as writers to appreciating a bit more of the opacity and inscrutability of Doyle's original. But we've learned something from the '70s—he's a human being rather than a Superman figure, as he was depicted during WWII.”

The best news for Sherlockians is that almost 125 years after Holmes first made his entrance in A Study in Scarlet, sales of the original books continue to be steady, and that the brand still carries so much power. Serious students of the canon can now use Leslie Klinger's The New Annotated Sherlock Holmes, which has sold 144,000 copies since Norton published the multivolume set in 2004 and 2005, as a comprehensive reference to more than a century of scholarship. Titan Books has recently started reissuing classic pastiches, like Barrie Roberts's Sherlock Holmes and the Man from Hell, due next month.

In February also, Minotaur will bring out the second anthology of short stories placing the sleuth in North America in as many years, Sherlock Holmes: The American Years, edited by Michael Kurland. In May, Mary Russell, Sherlock Holmes's feminist wife, returns in Laurie R. King's The God of the Hive (Bantam). In the spring, the U.K.'s Macmillan Children's Books will begin issuing a new series featuring a teenage Sherlock Holmes. In December, Pegasus will publish another Donald Thomas novella collection, Sherlock Holmes and the Ghosts of Bly.

As for other Holmes books in 2010 and beyond, as Holmes himself said in “A Scandal in Bohemia,” “It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.” The publishing world will know soon enough whether history is repeating itself.