Google has announced a major rewrite of their cloud-based office suite, Google Docs, promising better performance, an impressive list of new features and an overall slicker experience.

The new codebase has been an entire year in the making, leveraging HTML 5 and a completely rewritten JavaScript engine which takes aim at making Google Docs feel more like an ‘offline’ application. Specific improvements include Office 2007 file format support, easier document imports with a greater degree of accuracy, live document collaboration a la Wave, greater control over the placement of text, pictures, and much more.

The extra goodies come with a temporary caveat though: offline functionality will be temporarily disabled on May 3rd. There is currently no word on when offline functionality will be restored.

The new features are immediately accessible to all Google Docs users, however Google Apps account owners will need to opt-in before they can get the upgrade. With that in mind, feel free to give the new Docs a whirl and tell us what you think.