I will try to treat this topic with as much respect as I can, but this may be a rough road for some of you to take.
This is one of those topics where religious beliefs are given too much weight in the conversation. Those beliefs do not, and should not extend to someone else's choices in life. The fact that we allow this to happen at all is completely wrong.
If a person is terminally ill and doesn't want to suffer they should be allowed to choose the time and date of their demise, and at present, they are not given that choice. They should be given the option of seeing a physician who is comfortable with administering end-of-life care.
I have to take the conversation "there". Practically none of you have a problem taking your pet to the "rainbow bridge" when it's obvious that the pet's quality of life has seriously degraded. With pets, you don't even know if that's what the pet would want. With humans, no one (in this situation) is even asking you to make that decision, they are only asking you to let them make the decision for themselves.
What keeps this from being a legal avenue is I guess some twisted form of religious interpretation that "God will take them when he's ready for them". Then there's that weird hope that some people have that somehow in the few remaining days a person has that some medical cure will be available. To a lesser degree are those people who can't accept that then the end is near, and the truly evil ones who keep their relatives alive for as long as possible for financial or other reasons.
I think we're a little evolved to not only the dying one last wish, and yes, that includes doctor-prescribed suicide pills. If you'd like to join the fight, you can check out texasdeathwithdignity.org