The tech community should have a discussion about the best way to move forward with CSS, but it will probably turn into this:
http://xkcd.com/927/Like it or not, CSS has legacy support built into millions and millions of devices that cannot be easily updated. Newer versions can come forward, but more likely than not, the best thing to do would be to build on frameworks such as LESS (or one of it's cousins) that allows you to code in a meta language. Combine it with some static analysis tools and you can create a system that warns you when you cascade too much (for some value of too much) and help keep you sane.