I’m at that ten year mark when I need to replace all the smoke detectors in my house. I’m looking at the items on the market and in reviewing the Nest Protect I noticed a huge missed opportunity. I have a Nest Thermostat and love it. However, one shortcoming it has it that the temperature can vary a lot between where it is placed and the other rooms in the house. I have to put a smoke detector in almost every room to be up to code. If those also had a temperature sensor and could communicate to the thermostat then I could easily adjust or set rules when the bedroom is too hot or cold compared to the kitchen so that everything is the temperature I want as I get up or go to bed.
Other thermostats have dedicated sensors that you can place around the house for this, but since I’m already going to place thermostats around the house you could combine the two for a really elegant, simple networked sensor array. In fact they already have a temperature sensor in them, but it’s not currently used for this purpose, merely to detect rapid changes in the temperature that may indicate a fire. Seems like this may be something that could even be added using the existing hardware.