> which allows for running full X11 desktop environments using Wayland components

Wait so is this turning Wayland into a client/server model like X11, where eventually it could support existing window managers and other stuff separate from the compositor?

I remember a year or two ago wondering if that would ever happen and I think I only got one reply saying it wouldn't happen because it was unnecessary.

Yes basically. It's one full screen xwayland context you run a normal x11 wm in

IMO this is the real future of Wayland. It should always have been "mere plumbing" for X; the few processes that really need the isolation and security (e.g. screen lock) can be native, everything else should just keep using X, and the "in between" programs can mostly be X programs and implement some wayland protocols for the extra bits they need. Best of both worlds, no compat break.