Before I got totally swamped in the preparation of Drupalcon Szeged, I was playing with a module that uses a nodeAPI implementation for extra RSS fields, similar to Ian Ward's "views rss extra maker" in the developmentSEED sandbox. This Monday I finally committed it.
The module leverages the Views 1.0 field interface to give users control over the fields that will be displayed. It needs a minor patch to views_RSS (to add the $view variable when invoking the nodeAPI) to be able to do it's thing (nested tags, only specified fields). It also supports CCK fields with multiple values.
