Google has updated its Chrome OS to version 66, bringing with it numerous bug and security fixes. Chief among the security updates is a patch for Meltdown for Intel-based Chrome OS devices closing off the vulnerability across all Chrome OS devices.
https://www.notebookcheck.net/Chome-OS-updated-to-version-66-brings-Meltdown-patch-more.301614.0.html
The bigger deal is ChromeOS 67. We get full Linux support out of the box. So can use Stream games for example. Or traditional Linux applications. Only turned on with the PixelBook at this point but will be all CBs including ARM it appears.