Q:

Where do you draw the line between what is "embedded" and what is not?

ASIDE: Yes, this is can be considered a subjective question, but I hope to draw conclusions from the statistics of the responses.
There is a broad spectrum of computing devices.  They range in physical sizes, computational power and electrical power.  I would like to know what embedded developers think is the determining factor(s) that makes a system "embedded."  I have my own determination that I will withhold for a week so as to not influence the responses.

A:

I would say "embedded" is any device on which the end user doesn't normally install custom software of their choice.  So PCs, laptops and smartphones are out, while XM radios, robot controllers, alarm clocks, pacemakers, hearing aids, the doohickey in your engine that regulates fuel injection etc. are in.

A:

You might just start with wikipedia for a definition
http://en.wikipedia.org/wiki/Embedded_system
"An embedded system is a computer system designed to perform one or a few dedicated functions, often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. "

A:

Coming up with a concrete set of rules for what an embedded system is is to a large degree pointless. It's a term that means different things to different people -maybe even different things to the same people at different times.  
There are some things that are pretty much never considered an embedded system, for example a Windows Desktop machine.  However, there are companies that put their software on a Windows box - even a bog standard PC (maybe a laptop) - set things up so their application loads automatically and hides the desktop.  They sell that as a single purposed machine that many people would call an embedded system (but many people wouldn't).  Microsoft even sells a set of tools called Embedded Windows that helps enable these kinds of applications, though it's targeted more to OEMs who will customize the system at least somewhat instead of just putting it on a standard PC.  Embedded Windows is used for things like ATM machines and many other devices.  I think that most people would consider an ATM an embedded system. 
But go into a 7-11 with an ATM that has a keyboard (I honestly don't know what the keyboard is for), press the right shift key 5 times and you'll get a nice Windows "StickyKeys" messagebox (I wonder if there's an exploit there - I sure hope not).  So there's a Windows system there, just hidden and with some functionality removed - maybe not as much as the manufacturer would like.  If you could convince it to open up notepad.exe somehow does the ATM suddenly stop being an embedded system? 
Many, many people consider something like the iPhone or the iTouch an embedded system, but they have nearly as much functionality as a desktop system in many ways.
I think most people's definition of an embedded system might be similar to Justice Potter Stewart's definition of hard-core pornography:

I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description; and perhaps I could never succeed in intelligibly doing so. But I know it when I see it...

