As several have pointed out recently, book reviewing is a dying art. Newspapers are shutting down book sections (notably, on this side of the border, the Washington Post and the Los Angeles Times). Precious few can make a living as a book critic. Lamenters look toward a heyday in literary criticism as a kind of golden age. Nobody reads anymore, the sky is falling, Western civilization is going belly-up, etc., etc.
As an obsessive bibliophile and someone who does occasionally receive checks for reviewing books, I lament this passing as well. But the thing is, I also work as a film reviewer, and have been hearing and seeing this refrain in film criticism as well; many of my favorite film critics have been laid off in recent months, most notably Andrew Sarris at the New York Observer. But one can hardly argue that people are not watching movies anymore. It's not necessarily the lack of interest in the cultural artifact of the book (or film) itself that is causing this change.
I think the truth is unsurprising; as Laura Hazard Owen points out, bloggers are taking over. People do still read, and they do still watch movies, but they are also resistant to anything that reeks of a higher intelligence telling them what's worth their time, and unfortunately, much of journalism has created that divide. It's much more fun, and sometimes surprisingly useful, to find a diversity of people (bloggers, friends) who seem to like the same books you like and get their recommendations, as well as their criticisms.
Personally, I'll still read the NYTimes Book Review and Books & Culture, but I also get a good deal of my book recommendations from Goodreads and Byron Borger's BookNotes blog. Call it DIY criticism.