Funky/not-funky RSS. It doesn't seem wise to put in place a social pressure to remove evolvability from the living RSS spec. A reason additions haven't taken off so far is that extra elements have only been used for simple metadata. Whereas, if modules (in either RSS 1.0 or 2.0) were used to structure previously unstructured data, say: including the comments or Trackbacks information in XML rather than just in the description tag somewhere; breaking out the hyperlinks embedded in the description so it's simple XML parsing rather than hard HTML parsing to figure out what the post is linking to; any other supplementary information that it doesn't make sense to include as the post itself but could be interesting not just to aggregators but other RSS consumers (lowering the bar for Technorati-a-likes); a link to an RSS feed of all posts in that category, that can be spidered; experimental ways of addressing posts-in-RSS rather than in HTML; [more ideas here]. If a tool provider who constituted a significant portion of the market were to add useful, structured data to RSS feeds as a matter of course, properly modularised of course, how long would it be before consuming applications began to take advantage of it? Aggregator authors want to make cool reading environments, not get involved in politics.
(If these views weren't about RSS, they could be about Echo, it doesn't matter. An ecology in which the format can evolve is key. Besides, I've got more to say about the software architecture.)
(Structuring previously unstructured data is equivalent to putting handles on previously unhandled things, or making an address space for things that never used to have URIs. It's the grand sweep of virtual worlds through the ages, from the beginning of literature culture -- oh, and earlier still, rhymes and verbal patterns to handle concepts, to get around the complexity exchange limit. It's the big tide, the semiotcracy we're living in. Whether or not it's obvious how in an individual case it could be useful, it's how to allow unintended consequences, how to even talk about things. If something doesn't exist in an address space, it's like speaking without nouns [and there's a whole other story here, about the internet class system and who can and who cannot create those nouns, the URIs].)