Gnome Shell recently introduced a new notification system. Sadly it seems like GNOME Shell is going to duplicate a lot of the efforts from Canonical. Besides the notification system the application indicators also have similarities.
the Message Tray. You can see a short screencast demo here: http://www.gnome.org/~mccann/shell/mockups/20090630-demo
I was truly hoping that Gnome would continue the fantastic work Canonical is doing rather than starting over. The question still remains, what experience will Ubuntu 10.10 ship?