Apache Roller 5.1 is expected to be released "soon" (no fixed date yet available). For the Apache Roller trunk branch (i.e., upcoming 5.1), I recently cleaned out the language resource files of unused strings that have accumulated over the years and also introduced generic.* property strings for common functions (Save, Edit, Delete, etc.) that are used in multiple places to further reduce the number of strings that need translation. As a result, each of the language files shrank 25-35%, with the results browsable online. As one can see, Roller 5.1 will be shipping with support for English, Spanish, French, German, Russian, Chinese - Simplified, Japanese, and Korean. (By language support, I'm referring to the user interface for administering your blog--creating blog entries, managing comments, etc.--and certain boilerplate text within your blog templates. For writing blog articles and customizing your blog templates, Roller supports virtually any written language desired.)
However the non-English languages have only between 30-50% of the total strings (roughly 1800 in all) translated. Any strings missing will appear in the default English. If you're looking to deploy Roller in an office or school and wish to have better support for a given language, now would be a great time to check out Roller trunk from Subversion and submit a patch to our JIRA issue tracker, translating some-to-all of the missing strings of your desired language. IntelliJ IDEA Community Edition provides an easy-to-use editor to identify and translate strings present in the English but missing in the other files, and Eclipse offers similar.