Presumably this also means the end of Mir development too, with GNOME focusing on Wayland. Additionally, Ubuntu is ending development of their phone and convergence initiatives. Shuttleworth wrote today, "I’m writing to let you know that we will end our investment in Unity8, the phone and convergence shell. We will shift our default Ubuntu desktop back to GNOME for Ubuntu 18.04 LTS."
In place of focusing on Unity and convergence and phones, Ubuntu will double-down on their cloud and IoT initiatives.
More details via this blog post. Quite a surprise! More details to come.
Update: Find more thoughts in A Look Back At The Desktop & X.Org/Wayland/Mir Milestones Of Ubuntu.