It already works fine under Gnome, every major Gnome distro should be switching either late 2016 or early 2017. I cannot imagine Ubuntu Gnome not switching in 1

It already works fine under Gnome, every major Gnome distro should be switching either late 2016 or early 2017. I cannot imagine Ubuntu Gnome not switching in 16.10. KDE is a little bit more behind, but I'd postulate well working Wayland somewhere around Plasma 5.8 - we are going to see 5.6 come out in a few months, and 5.8 is the start of next year. KDE themselves have had to propose tons of extensions to Wayland itself to support functionality they use - server side decorations, screenshotting, key grabbing, etc.