Libxml2 is now more favoured xml backend than unmaintained expat. It should be used by default
Once again, a reference to the docs or a recent post is reqired, this time from dbus.
Whare do you have this information from. Please at a quote and reopen bug.
Oh, please excuse me for my poor English, please see explanation here: https://bugs.gentoo.org/show_bug.cgi?id=283191. Also I would like to post recent benchmarks responding to biases about libxml2 performance problems http://xmlbench.sourceforge.net/results/features200901/index.html. http://lists.freedesktop.org/archives/fontconfig/2009-January/003077.html
reopened bug
That's for fontconfig. I don't really know how dbus handles xml, but if dbus doesn't have any libxml support, it's an upstream bug/feature request. Thanks