If the federal (or state for that matter) government is going to make some law about this it had better be a damn good law, and frankly I don't trust our government to make some "one-size-fits-all" law that will protect individual freedom (not just the freedom to live, but the decision to live your life as you see fit). If there is a law passed, as many here have proposed, that says the state must always err on the side of life the result would be that any conflict that reaches the state level would be decided only one way. That means you better have a great way to decide what reaches the state, because that will really be the determining factor. I don't have a great way to decide that, and I don't think you do either.
Now people will jump in and say that Terri's case was clear-cut, blah,blah,blah, Michael's a terrible husband, etc. But I am not talking about Terri, I'm talking about where do we go from here? Terri's dead, but we're still here, so what do we do now? Do we want to change the laws and if so then how?
As bad as the present system is I have yet to hear of a better one. I think I am like most Americans in that I don't want my decisions made for me by the government if I am disabled. And I don't want the government telling me "well you should have had a living will, tough luck, buddy". It's none of their freaking business, they're plenty intrusive enough already.
That law already exists, it's called the fifth and fourteenth amendments of the Constitution.