See Encodings in man-db for context.
Yesterday, I uploaded man-db 2.5.1-1 to unstable. With this version, not only is it possible to install manual pages in UTF-8 (as with 2.5.0, although with fewer bugs), but it’s also possible to ask man to produce a version of an arbitrary page in the encoding of your choice, and have it guess the source encoding for you fairly reliably. This finally provides enough support to have debhelper automatically recode manual pages to UTF-8.
It’ll probably take a little while to shake out the corner-case bugs, but I’m generally pretty happy with this. Once the new man-db and debhelper land in testing, I’ll send a note to debian-devel-announce and push harder on my policy amendment.
Considering the historical state of man-db when it comes to localisation, and all of the dependencies and general yak-shaving that had to be tackled to get here, this represents the end of probably several hundred hours of work, so I’m pretty happy that this is out the door. The only remaining step is to add UTF-8 input support to groff, which fortunately Brian M. Carlson is working on. After that, we can reasonably claim to have dragged manual pages kicking and screaming into the 21st century.