I think you mean Weston. Wayland is the protocol, Weston is the compositor implementation. Though I don't really see Canonical using Weston - it is supposed to be a reference implementation. They like their WM candy. I'd like to see them adopt Kwin, since they apparently hate Mutter, so we have less fragmentation. And since Unity is written in c++ and the phone apps are going to be in qt, I guess having a qt based wm would make sense.