Google has been working on a new window manager called Aura that brings many features of a desktop OS. Chrome OS now has a desktop, a taskbar, apps are placed on the desktop, there's support for wallpapers and overlapping windows.
According to Chrome's engineers, Aura is a hardware-accelerated "user interface framework for Chrome UI" that offers "rich visuals, large-scale animated transitions and effects that can be produced only with the assistance of hardware acceleration". Aura is cross-platform and should "provide the foundation of a flexible windowing system and shell for Chrome and ChromeOS on a variety of form factors".
The latest Chrome OS release is only available for Samsung and Acer Chromebooks as Cr-48 Chromebooks will skip Chrome 19.