Many people involved in Free Software i18n know dealing with changes to locale data from glibc is a major pain. Changes take a lot of time to trickle into upstream glibc, and most distributions ship with a big number of patches to these files.
Denis Barbier has been doing lots of work on improving the situation by working around this bottleneck, and has been maintaining belocs, a fork of these files which aims to bring speedy fixes to locale data in Debian.
During Debconf5, he gave a talk about the internals of the locale data format, which was pretty interesting, and I used the opportunity to get a pair of locales, Catalan for Andorra and Catalan for France, which I had written some months ago. Shortly after Debconf, belocs included them.
This, and a little hacking on d-i Sergio has been doing lately for LliureX, mostly consisting on making d-i use belocs instead of glibc locales, results on a debian-installer that knows that Catalan is not only spoken in the Principat de Catalunya. :)
I wonder how many people reading this knew Andorra exists
(On a minor note, posting this screenshot made me find a translation bug... which I could only find now that d-i shows this dialog for Catalan...)