Updated
[~/aMule/amule-dev-cvs/po]$ make en_US.gmo
rm -f en_US.gmo && /usr/bin/msgfmt -c --statistics -o en_US.gmo en_US.po
459 translated messages.
As I told you, allthough you will be using this language when running aMule with LC_MESSAGES, LC_ALL or LANG set to en_US, there will be no way to select it (yet) in the language menu until after rc8 (the language code has to be rewritten). But surely it will be for 2.0.0 final, so don't worry about that
About defaulting to en_US, the default isn't en_GB either. the defautl is the text coded into sources (that is... ehm... something-like-english) hehe.
So, unless someone takes the time to arrange the bad strings in the code, the default strings will still be in that weird language some ppl like to call english or something
btw, i forgot to say it, thanks for the translation