If someone with a Chinese browser can tell you exactly what character encoding is commonly used for their text fields, then you just need to modify bomis's server configs to change the "Character-Encoding" line to that. Same for Japanese. If Chinese and/or Japanese browsers can be configured to use UTF-8, that would probably be best since that would enable simulataneous display of all languages, but I think most older browsers use ISO-2022 or something.
We intend to support everything. Unfortunately, we may not always know how.
As far as I know, Chinese words are not supported by wikipedia. Range 0x80 - 0xFF in a byte was used by Chinese operation system to represent Chinese words. However, wikipedia will not render those codes "as is". ) Any plan to support it?