So basically Wayland replaces the X protocol. (I had to run some things with ssh -X, and windowing on remote machines came back to me..)
And Xserver is replaced by another Compositor which is not specified, but poking around Weston seems like the reference one (towns in metro west Boston?)
No tearing would be nice (I watch someone weekly on a Manjaro install, tearing linux screen share, it can be unpleasant).
I'm assuming a lot this gets abstracted away by QT/KDE , Gnome/GTK so developers can just Develop. (probably at the expense of alternative desktops..)