The CSS 2.1 recommendation is surely among the most extenuating stories about web standards. Started about ten years ago, it was recently announced as a proposed recommendation. One could say "finally", but this is not the end. The fact is that in the meantime also the CSS3 modules came into life, thus getting the situation even more complicated and intricate.
I don't understand why it took so long to get to this point. It's frankly a conundrum. Well, almost. The sad truth about this specification is that one single browser (do you know what it is? wink) did take the control of the entire development process. For years. Why? Because it was the majority browser and its support to CSS 2.1 was horrible.
Another thing that slowed down the process during the last three or four years were the continuous requests for modifications on various chapters of the specifications. From an implementor's point of view, these were surely important adjustments. From a web developer's point of view, these were (and are) insignificant details.
The point is that web developers are not involved in the development process of the CSS 2.1 specifications. Though the mailing list www-style is open to them, they rarely propose or suggest something that is going to be discussed and adopted by the CSS Working Group and browser implementors. Honestly, this mailing list turned out to be a sort of private club for implementors, CSS WG members and high-level programmers from various software houses and big agencies.
The overwhelming majority of web developers stay in the corner, waiting for something they've been waiting for ten years. Someday they will probably see the light. Well, someday.