I just noticed the new #translatable module popping up via a note in a Drupal issue. Historically there was i18n module, which provided the de-facto way to build multilanguage sites. Then through some smaller modules, competition and somewhat different thinking came in with localizer module. Now that Drupal 6 aims to solve most of the groundwork with multilanguage request handling, but still lacks translation support for key objects like terms, menus, blocks, #translatable enters the space with an approach based on Form API. The module supports node translation with Drupal 6's approach and includes support for other generic objects. Maintainers are Daniel F. Kudwien and Stefan M. Kudwien, supported by Unleashed Mind. These guys also intend to submit core patches for Drupal 7. Way to go! Let's meet in Boston to discuss where Drupal 7 multilanguage support should be heading.