Linux Mint 12 comes with a brand new desktop, built with Gnome 3 and MGSE (Mint Gnome Shell Extensions). It is a desktop layer on top of Gnome 3 that makes it possible for you to use Gnome 3 in a traditional way. You can disable all components within MGSE to get a pure Gnome 3 experience, or you can enable all of them to get a Gnome 3 desktop that is similar to what you’ve been using before. MATE is the another feature that has included in new release.
About Linux Mint
Linux Mint is an Ubuntu-based distribution whose goal is to provide a more complete out-of-the-box experience by including browser plugins, media codecs, support for DVD playback, Java and other components. It also adds a custom desktop and menus, several unique configuration tools, and a web-based package installation interface. Linux Mint is compatible with Ubuntu software repositories.