We actually just cleaned up our CSS a bit, but agree that we probably want to make that part cleaner in the long run. Though I haven't found making changes particularly difficult.
That's good to hear, and I wish you success in your efforts to that end! Here is a very simple heuristic, which is very helpful in evaluating how clean your CSS is:
How many times does !important appear in your codebase?
The ideal number is very, very small. (There is a reasonable argument for using it on buttons, and similar utility classes with complex and very specific and universally immutable styling; doing a once-over of a typical LW 2.0 page, I see no cases that fit this profile.) "Zero" is a typical number of instances of !important in a we...
What are your first impressions of the public beta?