We implemented theme support as a theme component that you will find at 'src/modules/baseModule/theme'. Try changing the theme via header, you will find the whole application layout responding as well. We strongly believe loose coupling is the key to maintainable and adaptable code. To demonstrate the point for the theme component we do not use knockoutjs or backbonejs but plain jQuery event bindings.
For multilingual support we use RequireJS’s i18n plugin. Not all components on the sample have localized text, but atleast you can see the effect on navigation menu.