"Apple IIs were used as PLCs in the local industry replacing Relay logic. You could connect them to the security systems Radio Shack sold that used the house current to monitor the alarms."
I helped install an Apple II that was essentially used as an environmental monitor and control panel. The system was called "Tomorrow House." We installed it in one of the local hospitals.
The first computer I owned was a single board powered by an RCA CDP1802.The Galileo spacecraft was powered by several 1802's. I would think that a space probe would be considered an embedded application.
This reminds me of a funny incidence that happened with me many years ago. I had accompanied one of my friends for his interview in company named Wipro. It was a walkin interview, of course the HR team was sensed and they start shortlisting candidates who can be allowed for tech interview. My friend who was experienced in Setbox design (linux and VxWorks), the HR guy told him " you are not experience in embedded systems so we cannot allow you to go for tech interview". After hearing this I immidiately took a verbal discussion with HR and explained him how embeddes system work and how set top box is a good example of embedded system. HR being HR showed his ego and didnt allow my friend to even go in for interview. Companies should not allow HR to decide what an embedded system is. My friend got selected in one of the top product companies later.
One way to throw cold water on your fiery debate (don't spill the beer) is to agree that "embedded" versus "non-embedded" is an analog function, not a binary logic function (engineer's way of saying shades of gray). Some systems are obviously embedded, and some obviously not embedded. I subscribe to the "intended use by the manufacturer" distinction. If the device is produced for defined uses, and not intended for uses other than those intended by the manufacturer, it is an embedded system. Originally, cell (mobile) phones were embedded systems, smartphones are not. When smart phone folks were sitting at the pub, and decided to add a camera, I doubt that someone immediately said "and with the camera, customers can take a photo of a product bar code, and search online stores for competitive prices". Just don't see it. My iPod Touch is an evolution of a music player, but I have a units converter, hex calculator, audio oscilloscope and spectrum analyzer (OK, more of a curiosity than useful), audio signal generator, ham radio APRS display, a "clear sky" predictor for astronomy, etc. While the iPod Touch has a primary purpose as a media player, it is also intended to be a general-purpose computing platform. I wouldn't want to use it for CAD, or edit a high-def video produciton, but it is not an embedded system. The Windows-based DSO in your poll leads credence to the determination that "embedded" is an "analog function". Although it is in dedicated hardware, the manufacturer encourages installation of third-party software to enhance its function, so I see that as more of a shade of gray than a smartphone. I am happy to see that nobody has mentioned response time as a measure. That gets into the "real time" debate (coming up after the CPU/MCU debate), which is a separate classification. A data logger that measures temperature every six hours is hardly real-time by most standards, but I expect that most would agree that it is embedded. Not much else you can do with it, without modification.
@Sheepdoll....in some ways I think it is a bit of a meaningless debate because there are so many grey areas like this. But as long as it keeps us talking about things like beer and bacon and Hawaiian shirts and San Fermin, I guess it is all good :-)