Slashdot had this from roseability:

“Facebook have quietly added the ability to delete you account. ‘Deactivate Account’, under Account Setting, has become ‘Deactivate or Delete Account’, and when checked it purports to permanently delete your account and all information you have shared. Facebook is actually willing to erase your data permanently? They must be counting on very few people doing so.”

I have no way of verifying this but if true this is a step in the right direction.