Clearly X is not serving these needs today as well as we need it to, and while Wayland is an option for the future, it is not the only option.
Trust me when I say that Canonical would rather not have to focus on additional engineering to deliver our vision, but what we also don't want to do is build around another solution that ultimately won't deliver what we need for this wider convergence vision. If we did that, we would end up in a similar place as we are now, depending on technology that weighs us down in functionality, performance and maintenance costs."
http://www.omgubuntu.co.uk/2013/02/c...display-server Check out the comments section; he makes several posts.
I don't doubt that they could come up with something for the mobile side. After all you have Android and webOS and all the other solutions that have made it easy for vendors to plug their drivers in. I suppose Canonical could do something similar, or reuse some of that code, or at least reuse the concept. But converting that to the desktop = disaster. No doubt about it.
This "convergence story" which has become all the rage (Unity, Metro, GNOME Shell) is just dumb. There's a difference between providing seamless integration between a variety of devices and forcing a square peg into a round hole.