Google's Chromecast streaming dongle is getting a minor update starting today, according to the official release blog. Chromecast build 16664 includes persistent volume levels across viewing sessions, as well as improved support for the IPV6 networking standard and "improved DNS robustness." On top of that, Google says the new build includes the usual bug fixes and stability improvements.
The update will be pushed out to all Chromecasts automatically over the next week.
Source: Chrome Releases Blog