If this system is introduced I will be opting out even though I would previously have expected my DH to agree to my organs being donated after my untimely death. Simply because if I am incapacitated I want my next of kin, my DH, to be the one making all the decisions including organ donation.
I do not trust medical professionals who may make the rational judgement that the lives that could be saved by taking my organs are worth more than any slim chance I could recover. I know that seems far fetched but I don't care. I find it even more horrible, to think that my dcs or dh could have their organs harvested before I had the chance to say goodbye or even know they had been hurt.
The other thing is, that after a person has died, I do not believe their remains belong to them or to the state. But to their bereaved family. If the next of kin choose to donate my organs that is up to them. The wishes of the deceased are irrelevant because they are no longer there.