This will allow users to export their website (or parts of it), import it to Google docs and have it automatically translated by Google. A great help to human translators who will not have to start from scratch (which can be a daunting task, especially for huge websites) and to share their work and have it versioned.
That should be a relatively easy one to implement, as I already gained some experience with Google Spreadsheet and its GoogleTranslate formula when working on our i18n effort for localizing Magnolia UI.