Because of the high interest in the subject, a new dedicated Dev Board has been born: MPSMv2, a small ESP8266 DevBoard with integrated MAINS Power Switch!
For more details about: http://www.esp8266-projects.com/2015/04/p2-wifi-web-power-switch-for-mains-mpsm.html
NodeMCU Firmware upload process for the new MPSW v.2 DevBoard Module (ESP8266 Web Enabled Mains Power Switch) :
MPSW v.2 DevBoard Module - first run. Testing GPIO output pin used for Triac control:
MPSW v.2 DevBoard Module (ESP8266 Web Enabled Mains Power Switch) - Testing simple Web interface and init configuration for starting automatically after reboot:
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/