I've created this Drupal module to consolidate and add missing feeds into a single place. This module includes the following protocols: RSS 1.0 (rdf), RSS 2.0, Atom 0.3. It does not try to replace the existing RSS 0.92 feed that exists in Drupal core. This module is based on the atom module.

Note however, that this module breaks with the tradition of using urls like "/node/feed" and "/atom/feed" in favor of more standardized urls like "/index.xml" and "/atom.xml" (which justifiably could be aliased, but I don't see the point). I also added support for the syndication block hook but it doesn't seem to be working and I haven't looked into it yet.