Apple’s latest OS X Mavericks Developer Preview includes iBooks for Mac, according to tips from developers who have installed the new beta. The new iBooks app looks in line with what Apple showcased at WWDC earlier this year.
When you launch the app, your iBooks content from iTunes will be migrated over. Users are also given the option to login to their Apple ID to sync their iBooks collection from/with iCloud.
iBooks for Mac includes the same Collections, PDF reading, and other books functionality from the iOS version (except for the wooden bookshelf design). More screenshots and a video below: