[gmueckl]

The distinction can be maintained easily by limiting the application client in its ability to display fancy text. In fact, it should have very little support for styling and layouting should be restricted to some nested grid like dynamic system without pixel perfect control. Part of the predicament of the current web is the expectation that you get fancy corporate designs reproduced pixel perfect everywhere. Break that for applications and you will limit the viability of reader applications for content that should be served as documents.

Imagine a browser that throws out almost all CSS the moment it sees a form tag or a line of javascript.