John Haltiwanger wrote:

On Mon, May 25, 2009 at 2:00 PM, Arthur Reutenauer <
arthur.reutenauer@normalesup.org> wrote:

              Since Arthur implies that an XML output might one day be
feasible,

 Note that the final estimate for the stable release of LuaTeX is 2012,
but the backend features may be available sooner.  Many people are looking
forward to using LuaTeX for producing XML-based and other formats :-)
See http://luatex.org/roadmap.html for the roadmap.

Nice, glad to hear it. Also of interest are new semantic tagging facilities
for PDF in the newest proposal for ISO 32000, mentioned by an Adobe engineer
in the comments of this blog entry
http://digitalcuration.blogspot.com/2009/04/semantically-richer-pdf.html

Hopefully there can be found a way to incorporate these facilities in
ConTeXt and/or LuaTeX when they emerge.

as it takes a bit of work i'll only look into it when i need it (in a project) or when i'm extremely bored; it's rather doable