And we're told to not write down our passwords ???
Surely a far more practical solution (rather than going through the rigmarole of updating legal documents) is to simply have a postit stuck to the side of your screen with your passwords on it. Or for the ultra-security paranoid: stuck on its back!
The question then becomes, who is responsible for keeping up the subscriptions on all these wonderful, valuable e-assets? The ones who's hosting company's Ts & Cs you'd be breaking by either: giving your account details to someone else, or: accessing someone else's account.
That's even if you share the same musical/film tastes as your dear-departed. Or if all the stuff in their accounts would end up in the equivalent of a house-clearer's skip. Though would you really want to stumble across your grandparents' pr0n collection?