My take on this is that it will eventually replace the convoluted CSS that there is right now, as it is historically/hysterically grown. Future customization could then be based on this new system. Which would make it much cleaner and easier to maintain.
I would agree though, there are still features I would love to see. Maybe I missed it, but I would still like to see some kind of roadmap, to get a sense of direction where the project is going 
. Feature additional feel unfortunately very random.