The Zen of document style, pipeline based integration. Second last paragraph of Uche's piece evokes violent agreement from me:
"An alternative is pipelines of data, where a document starts out in one form and ends up in one suited for a different environment. This varies from the common approach to XML interchange where data conversion is a hefty process that binds one node to another, causing an increase in the needed machinery as the nodes increase. Processing pipelines minimize network complexities and maximize the usefulness of intermediate data forms. "
Amen to that.