So, I amended the Development policy on meta:

http://meta.wikipedia.org/wiki/Development_policy

...to the effect of: "Document new features in the User's Guide."

Every programmer in the world is too damn busy coding to communicate what they're doing, true. But if you add a feature to MediaWiki, you are the main person who knows about it.

We have a pretty darn good users' and admins' guide now. The more we keep it up-to-date, the better. It's quite easy to add a little bitty wiki page to meta.w.o saying what the feature is and how it works. It doesn't have to be any more complicated than what you put in a changelog summary. Others can then find your features, test em out, expand the doc, etc.

~ESP