I didn't see this is the national news, so it's fortunate that I happened to be visiting relatives, since it was on the front page of the local newspaper on Christmas Eve. A 62 year old woman, Sue Dawson, donated a kidney to an anonymous recipient. It's good to see positive coverage of such acts, to reinforce the message that organ donation can do a lot of good.
That said, I think live donation, at least to a stranger (as here), is more than ought to be expected from anyone. It's what philosophers call supererogatory, which means basically beyond the call of duty. Those like Mrs Dawson who want to do this should rightly be praised for their generosity and the good that they do, but others shouldn't feel bad about not volunteering their live organs.
The issue of posthumous (after death) donation, however, is different. Morally speaking, I'm inclined to think that most people act wrongly by refusing to donate posthumous organs.