Yet another thing Miriam Suzanne has been working on is a proposal for CSS Layers. I think it's a way of declaring what styles should "win" when specificity is equal instead of "last one loaded wins" or using the very crude `!important` tool. This could be particularly helpful if stylesheets for 3rd party components are loaded dynamically or on platforms where the style author doesn't have absolute control over stylesheet order.
All of these will take some time to get right and then some patience for older browsers to die off (or decent fallback strategies, I think all these would be hard to polyfill).
Now, CSS scopes back in the menu when?