FYI, no amount of life support is going to keep alive the body of someone who is brain dead. A semblance of life might be maintained for a short period, but without the brain to direct vital processes, it's not going to last.
I have personally seen people with less ability to interact with the world than Terri. Steven Hawking comes to mind. I don't think we need to be killing people just because they can't communicate well. Or because they're retarded, or autistic, or have cerebral palsy or some other neuromuscular degenerative disorder. We lost too many people fighting the Nazis to now turn around and start to embrace their methods.
Bravo!