Thanks, added.
Well, users can now switch between "default" and "UTF-8" language files.
On Joomla 1.0 "default" and on Joomla 1.5 "UTF-8" is used be default. Default does currently not only contain ISO-8859-1 character sets but also CP1251 (russian), ISO-8859-8 (hebrew) and UTF-8 (chinese).
So for chinese switching between "default" and "UTF-8" does not change anything