To get the launcher, just install a Chrome App from the Chrome Web Store, such as this text editor or note-taking app. The first time you install an app, the launcher will show up as an icon in the Dock. Chrome Packaged Apps for the Mac are available in the dev channel of Chrome and will be launched to stable channel soon.
In the meantime, you can build your own packaged app, upload it to the Chrome Web Store and give all of your users access to it via a direct link. Have questions about this or any other Chrome Apps features? We always welcome your feedback on Stack Overflow, our G+ Developers page, or our developer forum.
Posted by Joe Marini, Chrome Developer Advocate and Apps Aficionado