David Mudrak is now the new "Plugins liaison" in Moodle HQ
I think that displaying the available translations for each plugin listed in the Moodle plugins database will help Moodle admins of multilingual and languages-other-than-English sites decide whether to install a particularly plugin.
Currently there is not an easy way to know whether a particular plugin has been translated to your particular (non-English) language(s). The user must either look it up in AMOS or install the plugin and see.
The tracker issue MDLSITE-2289 'Consider displaying language packs available for a plugin' has recently been updated.
Please look at MDLSITE-2289 and vote for it if you think this is useful.