Copy-paste works, but primary selection does not, it was added to wayland-protocols just few days ago. Drag-and-drop also seems to be broken, I cannot drag urls to the terminal, for example.
Hmm, a few weeks ago Ctrl-C Ctrl-V didn't even work on Fedora 29. With the latest Nightly everything seems to work fine on Wayland, even dragging a URL to GNOME Terminal.
Also, without XWayland I have no artifacts when scrolling fast in long documents. Very nice :-)
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1585393
[2] https://bodhi.fedoraproject.org/updates/FEDORA-2018-2d42997a...