So... When Toady finishes the game, we will have created a world, which will evolve, and eventually wonder about it's own conciousness?
Also - Not true. Most animals don't have much brain structure apart from the Brain Stem, which is far more hardy than the more evolved brains that humans have. Chickens, for example, have their brain stem further down the neck (No actual evidence on this) or something, which is why they survive after having their head cut off. Once your brain cells die, they are dead. Which is why strokes are so fatal. That is where bloodflow is cut off from the brain, causing part of it to die. (Actually do know what I'm talking about here.)
That's the thing though; what defines a dead cell? Additionally, what is the ratio? If i take a single neurone from your brain and keep it alive, then kill you, will your soul therefore be attached to that neurone and denied an afterlife until it dies?
There are frogs (and a few other critters i think) which, during the winter, freeze. They are, by all current medical knowledge, dead. Their brains show no activity, their cells show almost no activity, they are, by our standards, dead.
Then, during the summer, they come back to life.
Finally, people who are 'brain dead' still have perfectly alive brains. They just have no electrical activity in their brain. The cells are just fine.
Would their soul still be attached to their body?
Finally; the reason why most creatures cannot survive being frozen is because cells are full of water, when frozen, the water expands and the cells rupture. Some finnish (i think) scientists are having a remarkable amount of luck using a special saline anti-freeze mixture, whereby they can rapidly replace a mouse's blood with this mixture and cool it down substantially. The mouse can remain in this state; with no measurable cellular activity and no nervous system electrical activity, for several hours, before having it's blood replaced and slowly warmed up until it is once again up and about.
I believe they started working on cats or dogs recently, and have been showing excellent progress. The process itself could be a potential life saver for millions heart attack victims every year, if it works on people.
It is very much possible to keep cells alive with minimal or no oxygen flow; the trick is to make the cells inactive before you cut the oxygen off; cells only need oxygen to do stuff, if they're not doing anything, they don't need oxygen.
Death used to be defined as "The point when the heart stops", this was because there was no known way to restart the heart. Then we worked out how to restart the heart, so we had to redefine death to "The point where electrical activity in the brain stops" (which turns out to be several minutes after the heart stops). This is because as of today, there is no known way to restart the electrical activity in the brain.
There's no reason to assume that doing this is impossible however; we can't do it yet certainly, but it's quite likely that in the not too distant future, we will be able too, and then we'll need to redefine death again.
Death is not as clear cut and easy to distinguish as you seem to think.