> Unlike the case of HTML, element names in XML have no intrinsic presentation semantics. Absent a stylesheet, a processor could not possibly know how to render the content of an XML document other than as an undifferentiated string of characters. XSL provides a comprehensive model and a vocabulary for writing such stylesheets using XML syntax.

So the big issue with XSL is that it's verbose as hell. I remember using XSL Transforms to do some really simple things, and getting it right was horrible. Debugging it was worse. Given a piece of code that uses HTML + CSS vs XSL, I'd pick HTML + CSS any day simply because it's more readable.

However, yes the core of it seems much better thought out than CSS.

> but now it's too late.

Is it? Is it possible to have some XSL FO to HTML5 + CSS compiler?