I have been reading the OSGi compendium specs all day:
http://www.osgi.org/Download/File?url=/download/r4v42/r4.cmpn.pdf
They include specifications for XML Parsers Services which may be worth looking at.
There's also specs for a Configuration Admin, though it seems to only support String key/value pairs, so I don't know how useful it will.
On an unrelated note, there's also a section for standard units of measurement.
--
Matt Stevenson.