The Chrome OS app launcher for Windows now means that users can tap into the vast pool of web applications instead of the traditional equivalents, including apps for document editing, Internet Relay Chat (IRC), and e-book readers.
Albeit, the feature may not be ready for prime time, as its still running on the developer's build, only available on Chrome for Windows developer version.
However, if you desire to give the feature a spin before the actual unveiling, you need to download the Chrome for Windows developer version from Chrome Dev. Channel.
Also note, you will need to install Chrome packaged app before you can see the Chrome OS app launcher on the taskbar. Already installed packaged app will need be uninstalled, and then re-installed before the Chrome OS app launcher may become visible on the taskbar.