I'm against it. Despite the obvious good intention, organ donation has to be a persons choice, in the same way that blood donation is a persons choice. A persons right to their own body is absolute, and whatever the intent, no-one should be able to change that. If this system was in place, i would opt out, not through not wanting to donate, but just because if i were to, i would do it through my own choice, and i fear many other people would do the same, which would surely have a large negative impact on organ donation itself.