We do not have any localized versions of BeOS, and none have been announced at this time.
In response to the overwhelming interest in the BeOS in Japan, Unicode support appears throughout the system.
The BeOS utilizes the Unicode UTF-8 format (the format used by Java) within all text objects and within the font system. This allows you to view documents, including web pages, encoded in many foreign languages, including Japanese. You can read some of the details in a Be Newsletter article, Unicode UTF-8:
http://www-classic.be.com/aboutbe/benewsletter/Issue75.html#Insight2
BeOS also includes a Japanese input method.
We still have work to do to support other multibyte languages, such as adding input methods, but this is a critical first step. Look for more details on this issue in the future.
Localizing BeOS is a non-trivial adventure, and we're looking into the possibilities of how to implement it. Again, keep an eye on this page, as it will change when there is news to be had.