I think anything that erodes our conception of each individual being able to happen to their own body, before or after death is an area with some very, very dark corners.
This kind of area should be treated with especial caution by any woman who believes that women have the right to chose whether they have children and how many children they have.
The attitude that it's ok to shoot political prisoners in the back of the neck and then sell their organs on the open market goes hand in hand with the attitude that it's fine for the state to tell people how many children they can have.
So any precedent for the state making automatic decisions about bodily autonomy needs to be treated with extreme caution.
I think organ donation is a decision that individuals should be encouraged and supported to make. And I do think that more people should make that decision and that more effort should be put into collecting the information.
Perhaps in the same way as screening, or voter registration- letter at regular intervals to ask what your position is. (Not actuall on the voter registration form or screening letter though- too heavy handed). it could even be like voting in Australia- you do have to register a decision periodically, but there is no presumption that the decision is one thing or the other.
We do seem to be heading in a direction where people are increasingly being treated as cattle who have to herded to the "right" decision by government, whether they, rather than being engaged and involved in a decision making process. And that is a worrying trend.
So I do understand why people who agree with organ donation but donit agree with automatic consent are coming from- presumed consent is a dangerous mechanism, it can give people in positions of power a bit of God complex and they get used to not having to ask for permission.
Life or death and emergency situations will always be invoked into pressurizing people into quickly making the "right" decision for highly emotional reasons, but that is so prone to manipulation. Accepting that kind of manipulation as legitimate is exactly what leads us to post-factual politics.
I heard Jeremy Clarkson say something awful about Jade Goody, along the lines of "What a hideous waste of organs". It betrayed an awful attitude- that someone else was just spare parts really. And I think a lot of people secretly hold that kind of attitude about other people.