After some tweaking with character set headers, title character limitations and mysterious high-byte problems, the Japanese wikipedia should now be useable: http://ja.wikipedia.com/
(At some point it and the other non-English wikipedias will be converted to the new software, but there is still work to be done before that's ready - see the thread "International upgrades" on wikitech-l.)
-- brion vibber (brion @ pobox.com)