As you may already know, the Red Hat developers are working hard at Wayland, a next generation display server that will slowing get adopted in RHEL, CentOS and Fedora systems.
Despite the fact that there is still a lot of work to do, Red Hat’s Christian Schallerhas announced that the plan to use Wayland by default on Fedora 24 is still standing. Among others, the developers have to implement proper menu positioning in Wayland, kinetic scrolling in GTK+, finish the tablet support and remove the X11 dependencies.
While they could implement it on Fedora 23, the developers have decided to wait for feature-complete release before switching the default.
Also worth mentioning, Fedora 24 server will drop the 32 bit (i686) architecture, but the repositories will still be there, for the workstation and the official spins.