A Document Author's Perspective

You mean all I have to do is my job?

Excellent! This is great! The document architect hands me a set of rules, the designer hands me a style sheet, and it feels like word processing!
Er... All our copyright notices seem to read "&cprt" on three of our customers' systems.
Uh... What do you mean I have to modify 450 documents to change stylesheets and DTDs? What's a processing instruction anyway?
Awesome! I always thought the document architect was a jerk! Now I can add my own elements and attributes, right here, at the beginning of the document!