The Wayland compositor has landed on Arch Linux, although not offering much at the moment, you can run X inside of Wayland (and that’s about it), because there are not too many usable apps that are Wayland ready. If  you only run apps made for X (ie. you are not developing any Wayland app or testing anything), you are only adding an additional layer with no extra functionality.

Here is the info straight from the Arch Linux dev-public mailing list:

Some news from the front:

– Wayland is in extra, thanks to Tom G. for moving it.

– Mesa and cairo have their wayland backend enabled in testing, thanks to Andreas R.

– Weston is in community-testing. You can now play with the first wayland compositor/windows-manager.

In case you want to test this you have to enable the testing repos in Arch (see the Arch Wiki Official repos page for information on how to do this).