Wayland-Protocols is the recently separated protocols from Wayland/Weston itself. With this first post-1.0 release, there are two exciting protocol extensions. But before getting too excited, the new protocol additions are currently considered experimental.
The new additions are relative pointer events and support for pointer constraints / locking and confinement. The relative pointer events will be important for first person shooter games and other similar scenarios. The relative pointer motions, locking, and confinement has been a long time coming and is also important for gamers. The relative pointer work has already been picked up by GNOME.
More details via the release announcement. The protocol specs can be easily read via the Git repository.