iBooks does a much better job at representing an ‘iOS 7-esque’ bookshelf than Newsstand by a mile. Hopefully, this teaches someone at Apple that a little bit of shadowing (used in moderation) is a good thing in interface design.
However, the app’s toolbars are a mess. For instance, the shelf selector widget thing in the titlebar is non-standard and doesn’t even act like you’d expect; it spawns a full-screen modal window when a popover is clearly the more appropriate choice. Also, the search bar is badly implemented. When scrolling, it doesn’t feel connected to the collection view beneath it. It works functionally, hiding and showing as it should, but it does not feel seamless.
More importantly, I get the impression that some of the navigation bars weren’t even spared a second glance by a designer … look at this atrocity. Like much of iOS 7, elements have been rushed.