Yesterday there was quick, airborne coverage of the GTK+ Wayland back-end moving forward
for GTK+ 3.0. Not only was the back-end merged, allowing the GTK+ tool-kit to begin working on this alternative display server that's quickly garnering attention, but it also works with the new GTK+ multi-backend capabilities.
This is the previously talked about work
that allows multiple GDK back-ends to be built into GTK+ at the same time with a single library. Kristian has brought the Wayland GTK+ back-end up to speed with this multi-backend support, which puts it a huge step forward. This allows a single GTK+ build to allow targeting to X11 and Wayland or other configurations too like GTK+ for Mac OS X supporting both X11 and XQuartz rendering.
It's talked about on Kristian's blog