The move to Gnome 3 and Gnome Shell was not Canonical's idea, it was the Gnome Project who decided their roadmap. Canonical in fact developed Unity because of concerns over Gnome Shell. Personally, I rather like Gnome Shell, especially with a judicious choice of extensions, but I have to admit my Core Duo 2 laptops do not always like a fully composited desktop.
Gnome 2 is obsolete, but lives on in RHEL 6 releases, e.g. CentOS/Scientific Linux/Springdale Linux with support until 2017 (apps and hardware) and 2020 (security only). External repositories provide newer kernels[1].
The MATE desktop is a fork of Gnome 2 built on libraries that are being moved forward. External repos for Debian Wheezy and mainstream packages for Debian Jessie. Mint also provide a MATE desktop[2], with the familiar Ubuntu package base.
A clarification: The classic look of Gnome 2 sort of lives in RHEL 7 since it will run Gnome 3 with Classic Mode[1] meaning that all that effort for a new UI/UX is wasted as the looks and the "user's workflows" will be the same as it was under RHEL 6 (IOW Gnome 2 like).
I take the point, and it is worth emphasising that the 'classic' mode is the default for RHEL7 installations when you choose Gnome as the desktop environment. However the 'mode' is skin deep - no customisation, can't remove panels, can't add panel apps &c.
I wonder how many EL 7 desktop users will opt for the KDE desktop now that both are presented as equal choices on installation?
Gnome 2 is obsolete, but lives on in RHEL 6 releases, e.g. CentOS/Scientific Linux/Springdale Linux with support until 2017 (apps and hardware) and 2020 (security only). External repositories provide newer kernels[1].
The MATE desktop is a fork of Gnome 2 built on libraries that are being moved forward. External repos for Debian Wheezy and mainstream packages for Debian Jessie. Mint also provide a MATE desktop[2], with the familiar Ubuntu package base.
[1] http://sohcahtoa.org.uk/pages/centos.html
[2] http://linuxmint.com/rel_petra_mate_whatsnew.php