RSS 2.0 or the Echo Project's new format, there's still a third choice: the other RSS. Tony Hammond covers it in a new article for XML.Com: Why choose RSS 1.0?
Discussing the RSS vs. RSS battle, Hammond writes:
It is difficult to know what is the underlying cause of all this angst. The principal suspect is surely RDF which is perceived to be somehow "difficult". Although built on a simple triples data model there is no fixed XML serialization since abbreviate XML syntaxes are supported, and it is thus not easy to capture this neatly in an XML schema language.
I think he answered his own question. I've tried several times to figure out the benefits you get from introducing the complexity of RDF to a simple XML syndication format, but I haven't found them yet.
Another benefit to RDF, not yet realized in practice, would be the interaction between vocabularies all sharing the same underlying data model. FOAF and RSS. RSS and catalogs of publications. People and projects. Projects and releases.
RDF loads into tools or RDF databases just like SQL records load into a relational database, using the URIs used to link the records together.
XML, using current specifications, isn't structured to allow the same thing, even in "XML" databases.
Ken - you're quite right, except this is already being realized in practice ;-)
The tools are available of the shelf in practically every language - APIs, RDF stores, query tools, but there are only a few apps (outside of universities) actually using them so far - specifically in the context of RSS, I can only think of NewsMonster and my own (far from finished) IdeaGraph.
It's worth pointing out too that RDF *is* a relational model, but geared more towards less structured data (as found on the web) than regular DBs based on Codd's model.
Minor point - there is no *single* fixed serialization, which isn't exactly the same.
But if you start using extensions then the whole simplicity argument for RSS 2.0 goes out of the window - there's little to choose between them syntax-wise, and the RDF version is a *lot* more versatile.
Yes, at the application level was what I meant.
With the tools now widely available, we're at the point where the developers in the wild should be going, "ooh, it's just a database, with all the records decentralized, I just need to 'bring local' the records I want, and whammo!" FOAF appears to be driving that "Aha!" moment much more than RSS/RDF did.