GDM on Wayland
The Gnome Display Manager (GDM) in Fedora 22 will default to the Wayland display server instead of Xorg. While the default GNOME session still uses X, this change brings the move to Wayland one step closer.
Wayland is a compositing display server, using your computer's video hardware for rendering. On systems where Wayland will not run, GDM should transparently fall back to using the X backend.
If you need to disable Wayland for GDM, edit /etc/gdm/custom.conf to reflect the following:
[daemon] WaylandEnable=false
Libinput used for input devices
Input devices in supporting environments, notably GNOME with Fedora Workstation and KDE, will use a new driver, libinput. The new driver replaces a variety of drivers, such as synaptics, enabling more consistent behavior across a variety of devices.
'libinput improves support for multi-touch devices and software emulated buttons. The driver is implemented directly in wayland sessions, and in X sessions through the xorg-x11-drv-libinput wrapper.
Input devices will be configurable through GNOME Settings, KDE System Settings, xfce-settings, or xinput. Some niche features are not available via libinput, but the previous behavior can be restored by removing the xorg-x11-drv-libinput package, and ensuring the appropriate x11 driver packages, probably x11-drv-synaptics or xorg-x11-drv-evdev are installed.
Note that xorg-x11-drv-libinput is only installed by default on new Fedora 22 installations, if you're upgrading and you want to use the new features provided by libinput, you can install xorg-x11-drv-libinput manually by doing:
sudo dnf install xorg-x11-drv-libinput
To learn about the features and behavior of libinput, refer to man libinput
or http://wayland.freedesktop.org/libinput/doc/latest/pages.html