The Chrome OS Beta Channel has a second build that has been released to testers this month. The new build is 64.0.3282.122 (Platform version: 10176.61.0) and it is available to most devices out there. If you are already running the first beta of the month, you can type chrome://help and check for the update to this new build.
This new build is loaded with a lot of bug fixes, performance improvements and other tweaks as the Chromium team puts the final touches on getting this new build ready for the Stable channel. You can read the entire change log here but the TL:DR version is bug fixes and security improvements.
The update to Chrome 64 on Chrome OS is expected to happen late this month or early next with this new build likely the final version. Assuming no major flaws or issues are discovered of course. This new build will bring a lot of improvements including improvements on how Android apps behave overall.
As a reminder, the Beta channel is still considered an unstable version of the platform so it is not recommended that users move to that channel unless they have a specific testing need. It is aimed for developers.