The mistake was that Wayland was submitted together with Xorg (Mesa is still OK IMHO). As it currently stands, the latter one will be slowly phased out and more interesting development will be in Wayland in next few years (it will still take time before it can be a ready to replace Xorg with the "glitch-free" layer for X apps).
Perhaps also previous attempts in GSOC didn't work well with these projects. Probably it is too hard for students, because of complexity and requiring a lot of heavy lifting and dealing with a lot of the old cruft.
I would really like to have seen X approved.
- We need XRandR 1.4.
- There is probably old code to be cleaned up, removed, deprecated.
- More work towards multi-GPU.
- Perhaps multi-touch needs maturing.
- Some of the features/merits of Wayland could be implemented in X.
- Work on X on Wayland and Wayland on X.