HTML issue 41 raised for Distributed Extensibility

http://www.w3.org/html/wg/tracker/issues/41
 
The HTML5 specification does not have a mechanism to allow decentralized
parties to create their own languages, typically XML languages, and
exchange them in HTML5 text/html serializations.  This would allow
languages such as SVG, MathML, FBML and a host of others to be included.
At one point, an editors version of the HTML5 specification contained a
subset and reformulation of SVG and MathML.  Tim Berners-Lee described
this incorporation of SVG and MathML without namespaces as horrific and
the issue raiser completely concurs with the him.  

This issue limits the ability of non-HTML5 working groups to define
languages as the languages must be "brought into" the HTML5 language.
This dramatically increases the scope of HTML5 and decreases the ability
to modularize development of orthogonal languages.  

In the end, the problem could result in the text/html serialization
rules becoming the standard serialization rules for XML languages,
replacing XML itself.  This could occur if every decentralized language
has a choice between the XML serialization, the text/html serialization
or both.  In many cases, the language may choose the text/html
serialization.  

This issue was first raised in August 2007 by Sam Ruby in [2] and also
raised at the recent W3C AC meeting by Tim Berners-Lee [2]
  
[1] http://lists.w3.org/Archives/Public/public-html/2007Aug/0134.html
[2] http://www.w3.org/2008/Talks/0421-ac-tbl/#(1) (member-only link
until Tim publishes in a public way)
 
Cheers,
Dave
(apprently I'm destined to raise thorny issues numbered 41)