An issue that seems more problematic in theory than practice is who inherits digital assets at death. Technically, the purchaser of digital content has acquired the "non-transferable" right to use the items. Theoretically, there is no right to leave these assets to heirs and it is very difficult to distribute parts of these assets among various heirs (i.e. R.E.M. collection to daughter, Eminem songs to son).
The simple solution is to share the password so that the collection can continue to be accessed post-death on whatever devices the decedent used (i.e. Kindle, iPod). Logistically, integrating an iTunes library into another library is very technically challenging and merits a visit to www.ilounge.com.
However, from a practical perspective, do children want their parent's digital media and vice versa? Growing up, my parents never had an album that interested me. Looking back, I still see no need for a Ray Coniff Singers or Mitch Miller album in my collection. Will others be worse off because they can not access a loved one's Lady Gaga, Lil' Wayne, or Black Eyed Peas collection? Will family members want to watch Cars 2, Transformers, and any Pirates of the Caribbean movie in the future, not to mention episodes of Keeping Up With the Kardashians and Two and a Half Men? I doubt it. If I am right, perhaps Apple and Amazon are doing people a favor by not easing access to the digital content of deceased family members.