Pantheon Mail is going to be the successor of Geary email client as the open source company behind it has been ceased.
Horst3180, the author of Arc GTK theme is now working on an amazing new icon theme. See a screenshot of the icons.
After 5 months of development MATE Desktop 1.12 has been released with better GTK3, touchpad and improved multi-monitor support.
See this desktop using Arch Linux as a base, running Gala window manager, Plank bottom dock and Budgie’s top panel. The theme is Arc GTK and the icon theme is Numix Circle.