Bookish is a joint effort between Simon & Schuster, Penguin Group USA and Hachette Book Group. It's still in private beta. There's a New York Times article about it: Publishers Make a Plan: A ‘One Stop’ Book Site

“There’s a frustration with book consumers that there’s no one-stop shopping when it comes to information about books and authors,” said Carolyn Reidy, the president and chief executive of Simon & Schuster. “We need to try to recreate the discovery of new books that currently happens in the physical environment, but which we don’t believe is currently happening online.”