Wayland and screen savers (UPDATED)
Wayland does not support screen savers: it does not have any provision that allows screen savers to even exist in any meaningful way. If you value screen savers, that's kind of a problem.
UPDATE
Another case:
-
JetBrains promises Wayland support for its IntelliJ IDEs on Linux – eventually [Ed: Microsoft propaganda agent Tim Anderson can happily gloat that Wayland leaves "Linux" back]
JetBrains will add support for the Wayland Linux graphics API to its IDE family based on IntelliJ – though the effort is “ongoing” and depends on Project Wakefield, an OpenJDK project to add Wayland support to Java.