Hi Owen,
I am not saying that every electronic component will suddenly interconnected with the Internet by itself but if you just look at regular hardware that you can buy today (like an Arduino) then you will see that there are limitations and those force developers to select a subset of the features they normally have. So, you have to decide what you implement and there are consequences of doing so. For example, you may not have a certificate revocation built into these devices.
An example quote from an IETF mailing list discussion:
http://www.ietf.org/mail-archive/web/dtls-iot/current/msg00015.html