The Google team have been working on bringing a rich notification center to Chrome OS for some time now, and it looks like it won't be long before it arrives on your Chromebooks. Francois Beaufort, the same developer who first gave clues about the new feature has provided a screenshot which shows the notification center in action.Users will be able to get access to the notification center through a new icon which will be available on the taskbar.
The Google Chrome OS notification center seems to have been influenced by Google Now and Android 4.1 Jelly Bean. The notification center will also include notifications from your Google Plus, alerts from chat and email, along with missed calls.
Another new feature comes in the form of a new icon which has been included in the application bar. Even though Beaufort did not reveal what the the app indicates on his Google Plus post. The icon features four messaging bubbles which indicates it could be related to a unified messaging app. In any case we should know more as the Google I/O draws closer.
source - +François Beaufort