Are there any examples to port existing WM from X11 to wayland? For example, porting light-weighted WMs (such as dwm, wmii, awesome) to wayland. Maybe, portings dwm to wayland is a good example.
Some guys are porting Mutter to Wayland and gave a presentation about it on FOSDEM 2012. Here's the link:
Copied from the website link:
Writing a Wayland Compositor
Neil and Robert will discuss their own experience of writing a Wayland compositor, where they have been adaping the Gnome Mutter compositor into a hybrid X and Wayland compositor. The talk aims to provide general guidance on writing a hybrid X and Wayland compositor without going into many Mutter specifics.
This might be a starting point for you...