There is a new feature useful for sites that want to let users access CiviCRM in multiple languages.
This feature allows admins to configure a list of languages for users to select from and set the language of the CiviCRM interface for their own use. This translates the CiviCRM interface but does not translate content. For example, the menus are translated but content and option values (eg Mr/Mrs) are not translated.
Users have a 'Language Switcher' block to make their choice, and the language can be specified in URL's.