Upstart was started before sytemd unlike Mir and Unity (in comparison to Wayland and Gnome 3) and it's creator having come in support of systemd[1], Ubuntu's upstream, Debian, going with it and on top of that Shuttleworth already admitting defeat. I have to seriously doub that.
[1] https://plus.google.com/111820116102071851808/posts/4eHMc2tv...