The Atom syntax is doomed because it will be dominated by the SyntaxFanatics.
The SyntaxFanatics hold us back because they're not really XML people at all. XML doesn't fit with the tools they use but it's a cool technology anyway.
The SyntaxFanatics don't like namespaces because the namespace prefix can be different in different documents which breaks their naive parsers.
The SyntaxFanatics like embedding full content in their feeds as text blobs because they think the only use for the feeds is redisplay in a web page.
The SyntaxFanatics don't like xml:lang because it means doubling up elements.
The SyntaxFanatics don't like RDF because it allows any element to be extended or replaced with a more specific version which breaks their regexs.
The SyntaxFanatics like to fantasize that everyone hand edits their feeds and yet those who do hand edit invariably produce ill-formed XML.
After long long experience with the SyntaxFanatics we end up resigning ourselves to the status quo. What we have right now works for me and my customers.
Derived from (RSS-DEV) Re: RDF redux (rant version)