WordPress MU

I want translate wpmu into chinese for my oser,but where can i get the most new language called *.po fiels?

a good starting point is http://codex.wordpress.org/Translating_WordPress

Maybe donncha could create a complete po as soon as every message is marked for translation.

And finally you can try and install the translation, it should translate a few things of WPMU already.
http://codex.wordpress.org/Installing_WordPress_in_Your_Language