In a blog post on Monday, Facebook brought attention to a previously existing feature intended to "memorialize" Facebook users who have deceased. You can submit a "Deceased" form (pictured below) that notifies Facebook about "dead" accounts. Once Facebook determines that the account owner is indeed deceased and flips the switch, no one can log into the account anymore, and the person's face no longer appears in friend recommendations or Suggestions. However, you can still post message's on the departed's Wall.
The problem with memorializing the account is that the user's family or friends, if they had the user's password, can no longer access the user's Messages or other personal data. (This could be good or bad thing.) For anyone in this predicament, I highly recommend you archive the deceased's account using ArchiveFacebook before their account is memorialized. Then you will always have a snapshot of the person's Facebook account on your own hard drive.
I'm giving a talk about the ArchiveFacebook Firefox add-on tomorrow afternoon in a Harding University Computing Seminar. If you're in Arkansas Thurs, feel free to stop by at 4:00 pm in Science 113.
P.S. This issue of "what happens to my data now that I'm gone?" is going to continue being more relevant as more of our data is stored in the clouds.