At my old job (which I left about ten days ago) I ran X servers and clients on different machines daily. Typical example was running my IDE on my desktop, connected to an X server running on my laptop.
The X developers didn't break remoting, but that doesn't mean contemporary gui toolkits still use the features of X that made X "network transparent." As I understand it, most features of the protocol are largely ignored except for the parts needed to pump bitmaps over a network.
The main reason, as best i can tell, is that every DE out employ OpenGL compositing that effectively bypass X.
Meaning that to draw the desktop they effectively pain a single large window inside X that is then filled with the output of the GPU.
Thing is that Wayland seems more comparable to svgalib than X. This in that Wayland pretty much a lib/protocol for talking to the graphics hardware. Something else, be it their reference implementation Weston, GTK, Qt, or some other alternative, has to handle the handling of windows, desktops etc.
Right now you can use Wayland as a driver for Xorg.
