Your are not far off
Your dishawasher will be controlled by your smart house controller.
IMO, there is nothing inherently wrong with that idea if I control it and control it via a device which is mine for which they supply information. I am slowly building something along the same lines myself in my house and I am not the only to reduce my power bills.
That however is not how a lot of players in this field see it. If you read most of the proposals for the Government Smart Metering consultations as well as the pre-consultation work by the Energy retailers association it is EDF, British Gas or the comms supplier like Vodafone who wants to do that and insist on _OWNING_ the equipment which controls it.
That would still have been fine (or kind'a fine) if the equipment was designed by the usual Internet, comms or even mass market retail players. That however is not the case - it is being design by the same people who design SCADA and industrial telemetry systems.
I have been saying this for years long before this Stuxnet affair - they are utterly clueless and oblivious to the way the real world functions. SCADA security is a joke. They think that by jacking up access control to crazy levels they have secured the system.
Wrong, the hacker's job is to circumvent access control and Stuxnet has show just how easy it is to do it with a SCADA system. We, who do real Internet work of any kind have know this for years.
The energy sector is yet to learn that. If it did it would not have tried designing smart meters running Windows XP embedded. Which is what it does now.
So, coming back to your question. How do you feel about _ALL_ appliances in your house _AND_ _THE_ _MAIN_ _OFF_ _SWITCH_ (that is what a smart meter is) being under control of a Windows XP appliance with userland code written by a someone who have never ever had to write any code exposed to a real Internet security threat. How do you feel knowing that this is connected to both a local network to talk to a display using a commoditity protocol, to a WAN and probably even to your local network to give you a daily dose of greenwash?
Are you feeling fine? I bet you do :)