Maybe we
should try to detect the language with javascript and offer the
choice that we guess is right, with the others hidden under a scroll.
Just added that functionality to Mediawiki:MainPages.js
I'm sure it could use a bit more love.
A link is added to the Welcome box for anonymous users if the browser
language is recognized.
Cool. But you should also try splitting the browser language by the
first dash.
Also, Firefox seems to always return en-US for navigator.language, see