Looks like a new Chrome OS build update is rolling out through the stable channel today. The update bring the stable build up to version 39.0.2171.85 (Platform version: 6310.48.0). In typical fashion the update brings along a number of bug fixes and security updates. While those are always good to see, it  is some of the feature highlights that are a bit more exciting.
The highlights from the update that has begun rolling out brings Chromecast support for media files saved in your Google Drive account. It also now displays apps installed in Google Drive in the Chrome OS launcher. While somewhat minor, Google also updated the Network Error page design.
Now for some bad news about the update. Seems that the Dell Chromebook 11, HP Chromebook 14, Acer C720 and the Toshiba Chromebook are excluded from this round for one reason or another. For everyone else with any other Chromebook you should be able to grab the update by heading to the settings in your Chromebook and then clicking on the build number at the bottom center of the page. Be sure to have lots of charge and a little time to download/update too. It seemed to take me about 15 minutes or so on one of my Chromebooks tonight.
Source: GoogleÂ