After a little bit of struggling with PHP (it’s been a while), I’ve exposed category specific feeds. Specifically, if someone wants to keep track of my Mozilla-related posts, here’s the feed (or the browser-oriented archive page). Similarly for ActiveState stuff (feed, archive), etc.
I haven’t yet figured out what tweaks are needed to my WP templates to make the feed exposed in the category-specific archives be the category-specific feed. It doesn’t look simple, as the category archives is really just a specialized search.