It's a pretty close clone of the new iPhoto '05 adjustment palette. Weird choice to base a theme on, you might say. And you'd be right. I just think it's unobtrusive, yet smart and sophisticated.
Best viewed as group bubbles. Incidentally, the status icons aren't the default ones - if you're running 0.8 SVN then click here
to get them - they're called Tiger style. Author unknown, but I made some modifications myself.
0.8 users: set the opacity at about 66% for best results :)