My initial reaction was like I don't agree with an opt-out system mainly because someone else has decided for you what happens with your body when you're gone. I think now though, that given the number of people who die due to lack of organs, it would be a relatively good system, more so as I do believe there's people who want to donate, but might not be bothered to go through the whole registration.
One of my worries though is that there might be some people who might not fully understand what it means, etc and it needs to be made clear to everyone that they have been automatically entered into a donor register. But how will they do it?
Also, I also respect people's sentimentalities over theirs, or their loved ones organs. While I might be willing to give my organs away, if my child was to pass suddenly, the last thing on my mind would be donating, and I would hate to think that they just took the organs without me knowing. It is not a logical thing, but not everything has be logical to be valid, and I agree that people should be allowed to feel how they feel about not donating. x