The discussion concerning MATE for Fedora begins with this Fedora development message. Eric Smith, an independent Fedora contributor, submitted review requests for mate-doc-utils and mate-corba packages, the first two MATE desktop packages. Eric suspects the review requests will take a while, but in this email he asks whether MATE should be considered as a feature for an upcoming Fedora release, like the Beefy Miracle or its meaty successor.
With that message volleyed, from there a very polarized discussion was sure to ensue. Questions were immdiately raised whether MATE is being actively maintained/developed (and whether it's anything more than a one-man project), whether MATE will still be around by the time of Fedora 18, and personal views expressed whether this project should even exist or if efforts should just be made to make the GNOME3 desktop (or Xfce/LXDE) better. Regardless, lots of people are unsatisfied with the GNOME 3.x desktop.
After MATE was brought up, another question was raised whether the Trinity Desktop Environment packages could be incorporated into Fedora. Trinity is a fork of the KDE 3.5 desktop, but at least that has been maintained longer and is a bit more successful.
Nothing concrete has been decided yet about MATE packages as part of Fedora but the discussion is still active.
The only major distribution that's shipped MATE as an official option so far is Linux Mint, but this GNOME2 fork is available for installation on Arch Linux and others.