Support for module texs in multiple languages, internally called "Content Localization" is on the roadmap for DotNetNuke 5, though it will not be included in DNN 5.0.
There are several solutions for providing page properties, including menus and breadcrumbs) in multiple languages, e.g. PageLocalization from Apollo and EALO from www.effority.net, available for free from the DNN Forge (see icon above). Besides, there are a number of multilingual modules, e.g. from Apollo, Locopon and www.portalfabrik.net, including MagicContent , available for free from the DNN Forge as well.