Hi, xmonad maintainer here. "nothing yet" is probably fairly accurate, although perhaps a bit too pessimistic. :-)

A slightly longer answer is in a bullet point on our fundraising page (https://github.com/sponsors/xmonad):

> Wayland: It's becoming increasingly clear that the days of X11 are over and some Linux distros are already switching to Wayland. We're committed to keeping xmonad on X11 stable and alive as long as necessary, but if time allows, we should explore the Wayland ecosystem and figure out what it means for xmonad. Do we go all in on waymonad? Shall we try to keep xmonad a pluggable window-management component for another Wayland compositor? Honestly, we don't know yet. This one is a bit of a stretch goal: we might need more than one person full-time to actually make this happen.

Elsewhere in this thread, I wrote about some concerns I have about waymonad and xmonad on Wayland in general: https://news.ycombinator.com/item?id=28796909 The gist of it is that I'd like to keep the compositor and WM separate, because a) xmonad is reconfigured by compiling/restarting, b) I don't think the Haskell runtime is good for handling input and presenting frames, c) I don't want to maintain a compositor :-).