I also hoped for a macro style color function that just text-replaces all occurrences of color: hackernews with #ff6600 when you define hackernews as def: hackernews, #ff6600; That would allow total mumbo jumbo style CSS-Sheets that look like Java or C++, if the authors would go that crazy..

However, I think that just copying how mixins and variables work in SCSS work into the CSS4 spec would do wonders. I'm 100% for it