I wanted to stress the aspects of my digital genealogy records I'm concerned about. Each of us has different concerns but you might think, "I don't really care what happens to my..." Facebook account or Ancestry.com account. What's important to realize is it might not go away (I'm a little freaked out every time Facebook recommends I share something with someone that has been dead for years) BUT no one may be able to access it. The post calls this a "legal limbo" and that is probably the biggest issue most genealogists want to avoid.
DNAFor me, the thing I am most concerned about is DNA results. In a limbo state, the results will continue to show up as a match for people, but can someone take your place to respond or use the results for analysis? See the Upfront with NGS post for a bit about others having access.
This is probably also an issue you want to address for any relatives who control their own results (as opposed to you administering their results---which means you have full control, already). I know it is pretty easy to assign a "beneficiary" for results from FamilyTreeDNA (it's under "Account Settings"). I don't know about the other testing companies. It's at least difficult enough I haven't stumbled across it and possibly doesn't exist (leave a comment if you have an answer). I know I've read online information (probably blog posts) about this information in the past. You can try a search if you want to learn more and check out the links in the Upfront with NGS post for estate planning information.