> It would be nice if there was a standard that existed allowing authors to simply write documents, saving them as models. Then, each device could read from a standard model file and, using custom controller code, generate a view displaying the text/images optimized for its display.

This standard is called "HTML". What you describe is the entire idea of HTML. Frankly, it's embarrassing that a web browser presented with a long stream of text won't keep the line lengths capped at a reasonable length.