As a none ubuntu user some stuff that comes to mind...

- Canonical sees it as their solution to a unified desktop between different devices, so they are not going to share this with other distro's.   Add to that Canonicals track record in doing upstream stuff and giving back I think for now that Mir will probably remain ubuntu only.  

- KDE (Kwin) won't do any upstream patches that are distro specific, I don't know Gnomes stance on that, but that would mean that Canonical needs to make kwin run on Mir or there won't be KDE on ubuntu... unless other distro's go Mir which I doubt (see previous point)

- I don't think this fragmentation is good for Linux, different desktop's, media players etc, etc is a good thing, different display servers is bad, it will be hard enough in the future to have X and Wayland support in drivers, rumour has it that nvidia is thinking about Mir support but then Canonical spread a lot of PR/Fud or whatever you want to call it when they announced this, for example posting stuff about wayland that was not true.  I personally have no seen anything from nvidia or amd about this and since nvidia biggest market is still the farms running on X I won't see that disappear fast, amd is another story I feel, but I could be wrong there.

- What worries me most though is that 5 years from now, will we have Windows, Apple, Ubuntu and Linux ?   Its sad enough to see games/application saying they only officially support Ubuntu. Right now we read that and know that since ubuntu is linux it will work on my opensuse/arch/mint/fedora/etc, with a new display server that will no longer be a sure thing and linux gaming might be back to where it was a year or 2 ago and we will have a www.gamingonlinux.com and a www.gamingonubuntu.com (might want to claim that domein Liam ;))

- But who knows, making a display server is no trivial thing, so maybe they figure that out and silently move towards Wayland or X-Mir on the desktop and keep Mir on (google's) phones and tablets.


edit: There has also been a good bit a commotion in the ubuntu community about Canonicals dissensions, read a rather nice blog here about how it sort of reflects opensuse vs suse/novell a few years back and how the opensuse community came out quiet alright,

I will just post what I first posted on Phoronix - pure insanity.

It does make me glad that the free drivers work fine for me though.

I'm sure if they went on a completely different path that they would at least release an API for applications designed to work on X to interact with it -- as such, I'm sure we would soon see a project pop up to interpret all calls made by native Mir applications to interact with an X server.

Still seems pointless -- would prefer they help improve Wayland and get it up and running properly.

Quoting: edgleyI'm sure if they went on a completely different path that they would at least release an API for applications designed to work on X to interact with it -- as such, I'm sure we would soon see a project pop up to interpret all calls made by native Mir applications to interact with an X server.

Canonical is taking a two-pronged approach to this.

(1) libSDL (the simple direct media library, a very widely used game portability library) has been ported to mir with the complete support of its maintainers.  Many existing games will be able to run natively on your phone, tablet, or desktop running Ubuntu, assuming the game was well written to take various form factors and input devices into account.  Newer games using SDL2 will be able to use OpenGL or OpenGL ES to get full accelerated 3D everywhere (older SDL1.2 never supported OpenGL ES).

(2) An xorg driver that runs on top of mir will let old legacy desktop applications run in a rootless window, just like on Mac OS X.  I'm not sure about 3D support through the X layer.

X is soooooooooooooo old though. I support Mir/Wayland's mission to replace X. The key is adoption.