I have long thought an opt-out system is a good idea. For the majority of people who are not on the organ donor list, it is simply a matter of not having gotten around to it, rather than actively not wishing to take part in the scheme.

An automatic opt-in system, with the ability for family to have the final say, is likely to lead to a far greater number of organ donations. 

If you feel strongly about not donating your organs, you can still choose to opt out. People who feel strongly about not donating, whatever their reason might be, are far more likely to take the necessary steps than the apathetic majority in the current system.