I support Canonical's decision of forking or going alone on project. In an ideal world, Canonical would not have to do this, but sometimes one has no choice to take full control of critical elements to get things done the way the view it.
Canonical wants to appeal to consumers, not developers. It needs to build a robust operating system which provides a rich experience, comparable of that of Android and IOS. And to get there, it needs to create something new and different (Unity) and have things working without being bothered with negotiations and compromises (Mir and Snappy).
Canonical created Unity because the two main desktops providing a rich experience, KDE and Gnome, are not designed for the mobile platform and there was no way Canonical could have influenced the KDE and Gnome teams to change their UIs accordingly.
Unity was created to bridge the mobile, tablet and desktop platforms. KDE and Gnome never had any intention to target the mobile and tablet platforms. Since these require a totally different approach regarding user input and display, Unity was created. What else could Canonical do?
And since January 2015, Unity is in the hands of consumers. Not developers, not geeks, not hackers, but actual consumers. It is being sold on mobile phones as a finished product. Congratulations Canonical. The desktop version still needs a lot of work, but it will be interesting to see it all coming together.
I would have loved that Canonical make use of Wayland instead of building Mir. But I understand why Canonical decided to go alone with Mir.
When Mir was decided, Wayland was moving along at a snail pace. It actually started to take steam when Mir was announced! And years later, Red Hat started to pay developers to work on Wayland. Why all this activity didn't happened before Mir was announced?
Despite all what has been said, as of January 2015, Mir is in production, in the hands of actual consumers and apparently, working very well on mobile phones. Wayland is about to land on Fedora by the end of 2015.
My only concern with Mir is support from proprietary drivers on the desktop; will the drivers of NVIDIA and ATI be compatible with it? If AAA games cannot be played on it, it is going to be a serious problem for Canonical trying to appeal consumers.
This is the new packaging system à la Android and IOS. This packaging system allows easier manipulation for the end user, offers sandboxing and has security built in. We need this and hopefully it could become a standard across all Linux distribution.
I do not believe that Snappy will displace .deb or .rpm. Not in the near future at least. It complements the other packaging system for a certain class of applications.
Unfortunately, Gnome is going by their own trying to develop another packaging system. Linux distributions must start seriously thinking of standard to be used across all major distributions.