It's not hard to see where the inspiration comes from for the new Ubuntu panel design- and particularly the notification area.
Clean, elegant, organised, functional, predictable, consistent...
Apple OS X of course.
Here are the Ubuntu Lucid Lynx notification area and the Apple OSX Leopard notification area for comparison:
Here for comparison is a standard Gnome notification area:
Untidy, scruffy disorganised, unpredictable, individualistic.... and colourful.
For some reason, I actually prefer the standard Gnome notification area.
But I'll just have to get used to a new notification area regime eventually: Gnome 3 is moving in the same direction: