Cinnamon 1.8 represents over a hafl-year of development with more than one thousand commits. Aside from a lot of bug-fixing there are improvements to the user-interface for the Nemo File Manager, away message support for the screesaver, Cinnamon Settings now handling all controls rather than the GNOME Control Center, and support for desklets. Desklets are similar to KDE's Plasmoids and Android's Widgets as effectively small applets for the panel/desktop.
Cinnamon 1.8 also introduces Spices Management as an easy way to install desklets/themes/extensions, a new settings API for applets/desklets, renderer improvements, better hot-corner configuration, coverflow and timeline alt-tab, and numerous other improvements.
More details on the new GNOME fork release can be found from the Cinnamon blog post announcement.