I've expanded this idea to cover several other common home automation tasks, and I plan to develop a network of modules to accomplish those common tasks (power/outlet control, lighting control, thermostat control, etc.) as well as timing/scheduling, logging, and monitoring of those tasks.
The aim is to power each module with an ESP8266 tied to an AVR. However, if free time and interest permit, I'd like to use this as an opportunity to build the toolchain and learn to write the firmware for these modules to be run natively on the ESP8266, bringing complexity, size, points of failure, and BOM down.