From the Official Kindle blog:
Amazon.com is excited to announce that The New York Times Book Review has now launched on Kindle as a stand-alone subscription. Each week, reviewers select 20-30 notable or important new books, including exceptional new authors. The New York Times Book Review has been one of the most influential and widely read book review publications in the industry since its first publication in 1896.
I'm a lttile surpised at how long this took. This was announced back in March.