Aria is a SunLeaf derivative board that replaces the ESP-09 modules with a ESP8266 raw chip integrated into the board. The idea behind Aria is that its a WiFi and ARM development platform that can run off lipo batteries and be solar charged.
Its essentially a more open ended SunLeaf as far as applications go, where as SunLeaf is aiming to be a node in a remote sensor network.
Aria will allow individuals to make wifi enabled devices of their own using the same technology as SunLeaf.
This looks wonderful, will really make low-power embedded platforms more accessible for hobbyists.