Simon's SlashDot link is full of fightin' words, some aimed at XML, some
at NoSQL, and some at MarkLogic. In the best tradition of Roger
Costello, let me quote of the ones that spoke to XML, here, and see what
comments at accrues.
"...XML, JSON and XQuery are all *data-interchange formats*. Using them
to run your database internals is like using a screwdriver as a hammer."
(which was posted by Chris Mattern)