A new version of RSS, superceding versions .9x and 2.0, is being created. Version 3.0 will provide more documentation of the language, “thereby solving common problems with the existing standards.”
This version will not replace version 1.0, which is based on RDF, or Atom. At this point, there are still 3 major competing RSS standards. Most readers deal with all of them.
This version will provide a full specification as well as a lite. RSS 3 Lite is available in draft form now.