A range of products, like lights, locks, and washers/dryers, are now becoming Nest compatible. This allows them to react to things your Nest thermostat does, or your Nest camera sees, or your Nest smoke detector… uhm… detects. The video shows lights coming on when movement is detected, or the drier will occasionally re-thumble your clothes where you’re not home.
The Works With Nest page has a list of all the products that work with one (or more) of the Nest products. It also allows you to sign up to keep informed of new products.