Effective immediately, the new release of Ubuntu, 17.10, aka 'Artful Aardvark' has been released!
This release will be supported for 9 months (until 2018) for Long Term Support, stick with release 16.04, instead.
Official flavors (e.g. Kubuntu) are also released.
See the above release notes for a full list of changes and where you can get a copy.
[Full disclosure: the majority of SoylentNews' servers run Ubuntu 16.04 LTS though we have taken steps towards moving to Gentoo.]
The customized version of GNOME that Ubuntu 17.10 uses is very much in the mould of the (now defunct) Unity desktop, so it won't be to everyone's tastes.
Mir got a LOT of flak, and deservedly IMO: they started development of it *after* Wayland was announced and started its development, so it became in effect a competitor, though Mark later tried to argue that they had different goals. There was every indication that they were doing it because of their phone project, to try to achieve some kind of vendor lock-in there, and it was distracting people (namely toolkit maintainers and application developers) from Wayland, and the feeling was that they should have been contributing to Wayland instead instead of fragmenting desktop Linux even worse.