Also we have xml:lang, soap:mustUnderstand, soap:actor etc. (these latter two often appear on their own outside the soap namespace context e.g. ebXML) etc. Personally I am not against namespaced attributes but there again I do not develop XML/XSL tools merely just use them so I am not au fait with the pain they may (or may not cause). As a developer once I "got" how namespaces work they have never really caused me much pain.

Making life easier for implementors isn't a realistic objective unless we're talking about a completely new technology that wipes the slate clean: implementors can't escape supporting the legacy. The objective now, I think, is to make life easier for content authors. Or am I mistaken?

Regards,