Apple is moving steadily forward on OS X Mavericks, releasing the Preview 7 version to developers today. The release includes a few extra wallpapers and a link to a new OS X Mavericks page that is not fully live, yet. There are also a handful of bug fixes that are detailed in the release notes posted by 9to5 Mac.
The latest Mavericks preview can be downloaded from the Mac App Store as a software update. Registered OS X developers can also download the preview from Apple's Developer Center.
Apple OS X Mavericks