First off, I am making a will real soon, and I'm making a living will at the same time. If you don't know, a living will is used when you are still living. (wow, that was smrt) It would be used in a stiuation such as Terry's. If I am ever in a situation such as hers, I want to be un-plugged. If I have to be hooked up to a machine to keep me alive....
It is really hard on the family. I know that there have been cases where people have been in a coma for many years and suddenly snaped out of it, but I can only imagine the stress and hardships my family would go through if I was in a situation like that.
Really, once you turn 18, you don't "belong" to your parents. When someone dies, all their possessions and what not go to the closest living releative. Both of my grandfathers have died. The first one was divorced so everything went to his kids. On the other side of the family, his wife, my grandma, got everything.

I think its a real good idea for everyone to make a will. It takes care of most of the problems that occure when there is a death. There have been a ton of problems after my most recent Grandfather died: seblings fighting over money and all that crap. I know when you are young you feel like you are never going to die, or you feel you have all the time in the world, but you never know.