His question was: "where is the conversion of numbers and dates?". Obviously MediaWiki "does" the conversion of numbers and dates, it is just not part of the library that enables what is most crucial for us in Internationalisation; the translation of the messages in more than 280+ languages.
My friend Andrew was thinking of extending the library with the conversion of numbers and dates. It makes sense to have them included however, forking this really new library at this early time is "evilish". Talking to Santhosh, the developer of this library is the thing to do. It is, because in this way any future improvements in the existing 280+ languages or the missing 6000+ languages will be shared by anyone who updates to this library.