I for one see great areas of improvement and possibilities inside the common house. Not that I'd wire up every appliance with a Wi-Fi sensor, but some data can be useful, if only for safety (falling asleep with the oven on: here a sensor could cut the power at a certain condition, or trigger the fire alarm, or ring up the firefighters).
Or you left the house and realise you left some of the lights on, just tell the in-car console to open the domotics app, and tell it to shut the lights off.
And the smart fridge, if RFIDs or its successor ever become cheap enough to be able to be printed on a milk carton, you could have your fridge's contents with you wherever you go, just open the app, look what's about to go off, or have it remind you to get extra supplies when you're near a point of interest.
If they'll let me I'll hook up a Nagios server to my coffee machine.