I want Wayland to ship as soon as possible, I'm looking at the situation in the most "negative" way so that if it ship sooner than I believe, I'll be happy, and if it doesn't, I'll not be sad. (Wayland has been close to shipping for a lot of time now, remember when Shuttleworth wanted to ship it in 12.04 as a developer preview? The good old times when Canonical didn't suffer from NIH).

Gnome should ship with Wayland considered as stable with 3.14, and (as far as I know), there's no plain to ship KDE on Wayland before KDE5. XWayland still need works, and without it no distro will ship Wayland. The proprietary drivers still need to come out (Nvidia might be at work on them already, but for all we know it might still be just some drawing on a blackboard - and let's not forget about AMD, that will probably take quite a bit of time).

Also "normal" distro (Mint, openSUSE, Fedora...) will probably take their time as well to ensure that everything is working. I'd expect to see some kind of experimental preview, then a version with support to both (but with the default still being X) and then a version with Wayland (and an X failback).

Probably I'm just being negative here, and if everything happens faster than how I think it will, then great! Also, probably just a generic "years" feels too much, my expected timeframe is/was 2-3 years.