Giulio Camuffo announced his custom Wayland/Weston shell today on the Wayland development mailing list. He's been working on this shell for a while that's written using the Qt 5 tool-kit with Qt Quick 2. It's now in a comfortable state so he's decided to publicly announce Orbital.
Among the Weston Orbital features are effects like exposè, a taskbar that supports minimizing clients, a modular user-interface made of widgets/applets, and there's a graphical configuration tool.
The code to Orbital can be found on GitHub. Embedded below are some videos showing off capabilities of this Weston shell.