Will Wayland, unlike X, be able to "know" about a full screen app, and not fire up the screensaver? I remember reading up on this, and X (or present KWin/Compiz) cannot know or be told when to hold off on a screensaver.
UPDATE: Apparantly my source was a bit one-sided, and X can be told to hold off the screensaver. This new fact turns my question into this: can Wayland be told there is a full-screen app and do the necessary things, without explicitely telling it to back off on the big red "Start Screensaver" button?