Sand Storm reprints a piece in the Toronto Globe & Mail entitled "The Great Fiction Crash of 2005".
This is strictly from a Canadian perspective, so I don't know if it reflects things in this country, though I note that one of the publishers interviewed says that Canadian best-seller lists tend to be dominated by American writers. A few years ago, at BookExpo America, the annual confab of the publishing industry, many publishers reps I talked to said that things semed to be trending in the direction of strongly narrative nonfiction. That didn't surprise me, given how often critically approved fiction tends toward atmospherics rather than action and incident.
The lead of the Globe & Mail piece notwithstanding, I don't think The Da Vinci Code has had anything to do with this. Doubleday bent over backwards to publicize The Da Vinci Code and reaped the benefits. That even people with Ph. D.'s found the book plausible proves only that people can actually be educated beyond their intelligence. Had Scribners done for Anthony O'Neill's The Lamplighter what Doubleday did for The Da Vinci Code, I suspect O'Neill's book would have met with similar success. I still think it will be around decades after Dan Brown's tripe has been mercifully forgotten.
But I have a review to get to work on. Here's the Globe & Mail's Top 100 Books of 2005.