wasnt that the plan right before the KDE guys did rush into wayland because MIR was announced?
No one "rushed into wayland" because mir was announced. The main difference is news coverage on anything relating to wayland and mir has increased because the "wayland vs mir" drama generates drama and pagehits.
And there's also lots of development work going on in other parts of the stack (like egl support in mesa) that makes wayland and mir possible. Gnome and KDE have been able to start ramping up their wayland desktop development because these parts of the stack have started maturing enough, not because of anything to do with mir.
what always amaze me of this flame wars with mir is that the stupidiest further from the truth crazy pulled of an troll ass arguments reach everyone at lightspeed but actual facts require a bazillion posts to reach ppl, well if you reached this post for some reason before post watch this
X12 assumes you still have SOMETHING in common with the X API.... Wayland doesn't. Wayland throws the entire book and the bookshelf out the window and says "Okay, Start from scratch. No legacy crap, no assumed backwards compatibility, clean break. Lets get this right this time. No stopgap-measures."
Also, X12 was never really coming to pass... That X12 page was basically a whiteboard of ideas of "If we had to do it all over again, knowing what we know now, what would we change from X11?"
A lot of those ideas got merged into Wayland, and if some other company wants to make X12 they sure can...but i won't be the X.org devs.