Theoretically yes, but that doesn't seem to be how "smart" devices are actually being programmed.

There's a IBM/Samsung project that wants to create a framework where smart devices move in that direction: http://www.coindesk.com/ibm-reveals-proof-concept-blockchain-powered-internet-things/

Slock.it basic model is also about creating infrastructure for this.

Current smart-devices often rely on a central server. If you buy a device from a startup that might go out of business you have an interest in there not being a central point of trust. Does that mean that success of Ethereum is a certainty? No, it doesn't. But a possible model of how success would look like is there.

It's also worth noting that various luxury brands have a problem with forgeries. There can be a clear chain of purchase for a smart product that makes it clear that the product is authentic.