Please note that i18n project is aimed at the 5.0 (former 4.7) release and is not (and won't be) a part of OpenACS 4.6. i18n currently gives package developers a relatively easy way to make the UI of their packages multilingual. It does not (yet), however help much in providing the actual content of the site in many languages.
Content Repository does support multiple versions of content and cr_revisions table has a locale column, so it does provide a good ground for multilingual content as well. The new CMS (work-in-progress) will AFAIK use this functionality and help in building international sites.