I really don't like MGSE. The reason I came to Mint was because of Unity on Ubuntu.
After using Mint 11, I messed around with other distros for a while and came back to Mint this month when I heard that Mint 12 was out. Without reading anything about the latest release, I installed it, only to my horror, to discover the abomination that is Gnome 3. I breathed a sigh of relief when I discovered MATE though.
I've seen a few screen shots of Cinnamon and haven't installed it (yet, will do tonight after work) but from what I've seen... I can see that horrid "top panel" and the big, shiny, simple looking menus that come with it. UGH! It looks like another "Unity-eque", "computing for toddlers", type of desktop environment... (I don't know much about it as I've only seen the screen shots and haven't used it, so do correct me if I'm wrong.)
I really hope that Linux Mint continues to develop and support MATE. I'm currently studying .NET & Java and have begun recently teaching myself python, if they want, I will help in any way that I can to support MATE. I know I'm not alone in the support of the Gnome 2 fork, there's a big number of people who prefer it.