Hi Pekka,
No, download of fresh translation file is not automated yet. Supposedly Rosetta should allow it, but the link does not seem to work - I've been updating translations about twice a day in the repository. I'll look into it and see how it can be fixed.
You can either use download link above or get an update (I recommend readonly - for your personal project - to protect private things from accidental commit to the public repo) from github by first cloning, then fetching an update and then merging. Are you familiar with git?
In fact - could you create an account on github so I add you to the list of committers?
Edit - you can also check on github when the locale/de/LC_MESSAGES/django.po
file was last backed up. You're at 64% now! Gotta catch up on my Russian!
Evgeny.