Sam Ruby and others (a collection of people on Sam Ruby's blogroll. Following intertwingly will get you there) are doing interesting things in fixing and empowering RSS feeds. Most notable accomplishment: True xhtml support for posts.
Not many will have noticed that many XML parsers (notable microsoft's) think my feed is broken because I live in a city called København in my native language. That of course is immediately fixed by mod'ing the feed to emit the new funky RSS with xhtml, so that I can have properly defined Latin-1 entities.

I think that alone is a good enough reason to score a point for Sam Ruby and careful, well done XML use instead of just colloquial XML ('stuff in tags'). When I look at XML capable open source tools, the XML handling is always terrible. Parsers routinely require certain namespace prefixes to be used for certain elements they are interested in, instead of locating and processing the name space declarations and prefixes in use in the current document. They never validate and the layering is always bad. The information model of the data presented in XML is rarely made explicit. Data is picked from raw XML with great bluntness instead.

And finally as a perl hacker I must admit I find the profusion of simple, but incomplete tools available on CPAN to handle XML confusing and limiting. It would be great with a perl-like complete accepted standard of tools doing ALL the xml core features: raw xml, schemas, namespaces, xpath, xslt's etc.

(more notes on the battle for RSS)
(Ruby's community initiative for a shared standard)
(Perl and XML API's overview)