It seems that manadated choice concerning organ donation is a step closer, with proposals that those applying for a driving licence will have to say yes or no. (The BBC article gives the impression that this change has, or at least will, be implemented, but in fact it seems that it is simply a proposal at the moment.)
It's not much of a nudge, since it doesn't direct people towards answering yes, as some have proposed. Nonetheless, simply requiring people to confront the issue is likely I'd have thought to lead to more opting in, rather than simply passing over the issue. Even this, though, seems to have roused a lot of opposition, judging by the comments on the BBC story.