So, the interesting little ESP8266 WiFi SoC finally has a younger brother which appears to be even more capable. Among other expansive updates, the 32 bit Dual Core microcontroller still supports WiFi, but also Bluetooth Low Energy, a DAC, many more ADCs, GPIO pins, etc. etc. Lots of good details here: http://esp32.net/
The ESP32 is now avaialble to buy directly as a chip, or on small development boards. Unfortunately however, everywhere is currently sold out, so it will be a while before I get one.
The feature which particularly piqued my interest, however was the mention of CAN 2.0 support. I have already used the ESP8266 in combination with an MCP2515 to create a CAN to Wifi gateway, but if the ESP32 supports CAN on board, then this could potentially lead to a single chip solution.
There are already a number of other microcontroller which do offer CAN bus support (actually the list is probably huge since nearly all automotive and industrial spec controllers will) but for example the Arduino Due (Atmel SAM3X8E ARM Cortex- M3 CPU)