When message catalogs have been extracted from the Zwiki page templates, I assume it will be possible to use any appropriate characters in the translations.

Currently the default skin sets 'content="test/html;charset=iso-8859-1"' in the HEAD. A comment on InternationalCharactersInPageContent recommends 'charset=utf-8'. Customize the 'wikipage_macros' template to change this. What effect will this have ?

The zwiki_plone skin's charset is set by Plone, I believe.

See also TranslatedSkins?, #677 ZWiki locale support overrides PlacelessTranslationService