Of course. Many sensors use I²C already, so it would be extremely easy to hook them up. So a sensor-loaded OH seems trivial. Barometer, colorimeter, temperature, humidity, hal-sensor, gyroscopes, magnetometers, sound decibel, lux, ultrasound distance meter, radar (Nokia was already toying with that concept), PIR sensor, 433MHz tranceivers for home domotica... You name it. Also, put a CAN-transceiver in there and you can use the Jolla as extra console for your car, getting more, and more accurate readings from the car's sensors. Perhaps even tweak settings