I think most people are on the right track when it comes to semantic XHTML/CSS. CSS rules define layout. Tables are for tabular data. Etc... We all know this. But to get your head completely around this concept you have to consider accessibility.

Your pages aren't just displayed in IE on a PC, they may not even be displayed at all! It could be a text reader, and think how a table design might be interpreted by that. Someone might be dyslexic or visualy impared and require a custom colour set. What if someone prints your page, or is viewing it on a mobile device? This is why we use CSS, and should consider using multiple CSS files to include popular devices like screen, print, and mobile.

This might seem like a lot of hassle, but this is accessibility and nobody should be discriminated or alienated. Even from a business point of view these people are your audience and in the end they too will help keep you in business.

I know it's a horrible thought, but read http://www.w3.org/ It actually makes a lot of sense.