If you watched Apple’s keynote and browsed through the OS X website, OS X 10.9 seems far less visually polished than its younger sibling. We saw only one flagship OS X app that adapts to Jony Ive’s skeuomorphic-less future: Calendar. Other apps, like Safari, have flattened button styling in its new Reading List and Shared Links areas, but still retain bubbly gradients for its top bar. New apps Maps and iBooks (brought over from iOS) contain more of Ive's new look; iBooks even has a title bar that eschews the traditional OS X aluminum gradient for a lighter, flatter version. But that title bar isn't app-wide—go into the iBookstore, and you'll return to the aluminum siding of old.
Dig into Apple’s website a bit, and you can find hints of app redesigns not shown at Monday’s keynote. A small shot of Contacts in the Multiple Displays section shows a book-less app with no pages and ribbons to be found. And dark linen seems to have been universally erased from this timeline, with a simple grey background to replace it.Mac OS X Mavericks