Yes, zhwiki is still an issue because of LanguageConverter. I will be fixing that issue in both Parsoid and the PDF renderer. (As soon as I fix some long-standing bugs in image handling for Parsoid/VE.)
It's a bit tough to test the renderer on-line at the moment, because you have to import your own non-English content into the test wiki. I recommend trying things out off-line if possible. I can also email/post sample articles if you like. RTL languages should be well-supported; I spent about a week getting the details of the bidirectional algorithm correct. (And of course we inherit nice ligatures, etc, for Arabic from the XeTeX engine.) --scott