typester blogged how to get the current encoding of the terminal and that's exactly what I want to do with Plagger logging system as well. Hence I emailed Audrey about the possiblity to extract the encoding() method from Locale::Maketext::Lexicon and package it up as a separate module. She replied yes.
So here it is: Term::Encoding, my latest CPAN entry. I tested the module on Debian Linux and Win32 both on Japanese platform. Testing against various language/platforms will be appreciated. Try it from svn.