Part of the problem is the terminology. When I use the term "vegetative," I mean "comparable to a vegetable." It is my understanding that vegetables are not sentient; they do not feel pain. Therefore, if a person is capable of feeling pain, I would not consider him to be in a vegetative state.
If the medical community is not 100% sure that a person cannot feel pain, it should not refer to his state as vegetative. :-)
The problem with the medical community is that they are very, very often WRONG. No matter how "100% sure" they claim to be.
In the Schiavo case, there actually are differing medical opinions. The judge, for his own personal reasons perhaps, has chosen to give credence only to doctors who side with Michael Schiavo.
I think the article I quoted (you can read the whole piece by clicking on the link in post 35) proves that there IS "something going on there" -- in the brains of persons in a "vegetative state."
They may not be able to show what they are feeling -- but they ARE feeling.
I think we would be wise to never use the term "vegetable" to refer to human beings. First, no vegetables ever have souls - all humans do, regardless of their physical condition. Second, use of the term implies a less-than-human existence in which those who hate life are quick to glob on to in order to legitimize the murder of such persons.