I haven't really followed Wayland very closely but as a huge fan of tiling WMs (I've used StumpWM for more than a decade, although I switched to dwm lately) I've been a bit worried by the claims that Wayland doesn't have a window manager per se etc... Although I admit that's mainly because I haven't taken the time to understand what Wayland is exactly.

Just in order to aleviate my fears, can somebody tell me if in this brave new world it'll still be possible to effectively implement something like DWM or some other tiling WM "within" Wayland? Are there pitfalls I should be aware of?

I suppose there's got to be a way to do custom tiling, but I worry that there might be other less obvious limitations. For instance every time I attempted to use custom "window manager" on Windows (to add virtual workspaces for instance) I quickly noticed that it didn't work very well. One problem was that the window management was cooperative instead of preemptive: when the "window manager" attempted to hide a window it'd basically send a message to the application requesting that the window be minimized. If the app was frozen or simply uncooperative it'd remain where it was. Could that happen in Wayland?