It's true. One example of IE-only CSS is the
behavior: rule, which lets you add functionality to your browser by linking to external files. It's nice in principle, but there's no way that could be standardized across several layouts and platforms.
Another one is the
expression: rule, which lets you use JScript (IE's attempt at JavaScript) to determine values for a style dynamically. For example, I could determine how wide a certain form would be by taking a certain paragraph's width and subtracting 40 pixels. I can really see the value in this one, but it really does go beyond the scope of CSS, and using JScript or JavaScript for layout is really bad form. Also, proper support of modern CSS standards would largely reduce the number of times you would need to use this feature.
Jonathon VS
Freelance Web Artist
www.jonathonvs.com