One 5-minute visit to the website CSS Zen Garden, and I am completely sold that CSS is the way to go. The Zen Garden is a pleasantly designed web page, with clearly deliniated regions which provide a heading, a main body, a vertical nav bar, and a few other components.
It talks about the important lesson of the masters: Don't mix content with presentational data.
This is a great concept, much as the idea of separating presentation from business logic in a two- or three-tier architecture. But often the two start creeping back into one another...
But after you read the motivational words of wisdom, you discover a menu of other style designs from which you can select. Basically, clicking on one of the designs results in the re-display of the same HTML file, but using a different style sheet.
The results are stunning! It is as if you have visited an entirely distinct web page. But as you read the content, you realize it is the same... the content, that is.
Visit the CSS Zen Garden, read the wise writings, and move some of the objects around (i.e., select other designs), and you will see the light. There's no question that CSS is the ticket to site consistency, design control, significantly reduced development (and redesign) time, and faster load times for visitors to the site.