Please note that the up-to-date list of language pack maintainers and contributors can be found on this site, by clicking the Translation credits link at the top of each page (below the site logo). It's updated automatically, so there should be no mistakes (in theory!)
Previously, the translation credits page was maintained manually in Moodle Docs. http://docs.moodle.org/dev/Translation_credits lists translators from the beginning of the project (pre-Moodle 2.0) and is no longer updated. Maybe we need to rename the page to make it clearer that it is not the up-to-date list of language pack maintainers?