PC World reports that the APIs included in this latest Google Chrome OS update is Web SQL Database API. This new feature allows for storage of data in a structured manner, which is a language that your computer knows.
Saving small amounts of data is now made easier with Web Storage API, WebSockets is another API added, this allows information to be sent over persistent bi-directional communication channel. There seems to be a pattern to this latest update, it is more about API than any other feature.
Some of the best features for web browsers are their extensions, the latest in Chrome now gives the user more functionality when visiting a website. Users will now be given alerts along with notifications and icons with your favorite Web services right next to the address bar.
Google are still coming under fire for not offering support for Linux, they need to start thinking about adding Linux soon if they have any hope of making gains in the tough browser market.