Clues that Google is planning to bring elements of Chrome OS to its browser for Windows, Mac, and Linux have been popping up periodically throughout the last few months, with the latest evidence being a Chrome OS web app launcher built into the new build of Chromium. According to a Google+ post from engineer François Beaufort, Google is working on bringing the Chrome OS app launcher (pictured above) to the Mac, and users can try out a beta of it now. You'll need to install Chromium and then run a quick command in terminal — after that, clicking on the Chromium dock icon will bring up a grid of your installed web apps from the Chrome store.
Clicking on one of those apps will open the browser windows in full with the selected app. At that point, the icon reverts to its usual purpose of bringing Chromium windows to the forefront; if you want to open other apps up, you'll need to do so through the browser window itself. Right now, it's little more than a curiosity — you'll need to keep your terminal window open, and it's useless if you want to quickly launch multiple apps. That said, a fully-baked version of the Chrome apps launcher would definitely be a nice addition for those who like to live in Google's ecosystem. There's no telling when this might be finished, but rest assured it'll be here sooner or later.