Right now, if you die, your digital assets are essentially inaccessible, unless someone has your password. Facebook and other services allow you to request "memorialization," which essentially preserves an account in amber, but it is a violation of Facebook's TOS for someone to log into an account that isn't their own. In the case of things like iTunes, the company has complete discretion over what happens to the thousands of songs you've bought the license to play. Yesterday, the state of Delaware became the first to require companies to give heirs access to these digital assets, with the Fiduciary Access to Digital Assets and Digital Accounts Act.
Provided it appears in a person's will, heirs in Delaware will now have access to social media accounts, blogs, iTunes, emails, and cloud storage like Dropbox.