Jeff Croft just published an article about the attempt of separating content and presentation with HTML. He writes: “[T]he idea that a redesign of anything more than the most basic of sites will not require changes to (X)HTML markup is simply a myth.”
Of course he’s right and here’s why: HTML was never meant to be not altered on a redesign, because a HTML document doesn’t contain only content, it also contains structure. It’s quite important to take that point into consideration when talking about this issue.
XML contains the content. A headline, body text, a picture reference. XSLT then adds the structure. The whole content should stay in a
class="hentry" and the headline will be in a
h1. It indeed is like templating in modern CMS, like using smarty or another php solution (like wordpress does) or something like Textpattern with it unique XML like tags.
If you’re doing a redesigning, let’s say going from a two to a three column layout, that’s not only a matter of changing how the page looks like. The whole structure of the site may change in that step. And that change should be reflected in the markup, too.