As an old I18n/L10n tools hand (my first engineering jobs were in this general area), I'm curious what a less technical admin trying to get up a site in Japanese or Arabic finds difficult right now. Also, is there a list of general features that European or other non-English language coders notice as being general pains in the ass (such as bad phone/postal code UI, etc).
Don't know about Japanese, but Arabic has unique issues with the whole Right to Left thing. As far as Drupal and Arabic goes, here are some resources: http://baheyeldin.com/arabization/using-drupal-with-arabic-and-other-right-t... Note that other Semitic languages share the right-to-left issues, such as Syriac, Hebrew, and Amharic, as well as many other non-Semitic languages that use the Arabic script (Farsi, Urdu, Pashtu, Dari).