The technologies on the Web over the last five years alone have improved greatly and support for those technologies has improved as well. Five years ago design on the Web was a myth; the Web was for simple documents... just paragraphs, headers, horizontal rules and all on an ugly gray background. Over the years we have seen the technology improve quicker than we can keep track of. In this mad rush we attempted to adopt the new technologies before really understanding how they were intended to work.
Today things have slowed down a bit and it has allowed us to look at what we have created and see not only the flaws in the technology, but even more so the misuse of the technologies. We are going back to our roots of basic document structure for the sake of portability, interoperability and even accessibility.
The separation of style from content has been the cornerstone for cost-saving web measures. Those who didn't learn that the content needed to be separated are finding themselves going back and rebuilding a lot of what was already created in order to develop sites that are, in my words, forward-thinking, meaning that the site isn't just built for what kinds of technologies we have today, it's built for what is to come tomorrow.