During the OS X 10.9 Mavericks segment at WWDC 2013, Apple has pulled the wraps off the latest and greatest for Safari. One of the neat new features is a new sidebar with access to your reading list and shared links from your Twitter friends. The sidebar sits off to the left and allows you to keep it there while you browse through your favorite websites from your bookmarks, reading list or shared links.
Also, when reading your saved sites on your reading list, when you hit the bottom of the first article, Safari will just keep on scrolling right through to the next one. Pretty neat!