We are social animals. We live within culture as fish live in water. Our life and identity extend beyond just our bodies into and through the extensions of ourselves that we build up - clothes, houses, families, family, friends, reputation, writing etc. The life or death of our RL body is overwhelmingly important, but so is our social life and death. If someone's body dies we know they have not all gone if their social impact is still there: in what they did and made; in the difference they made on others' lives, in the memories we have of them, and in memorials of them. Similarly we suffer little social deaths (as well as new begginings) all the time: the loss of a lover or friend (actual or potential); a blow to our self-image or reputation; a withdrawal due to illness; or a child separating off to make its own life.
In SL the difference between our bodily life and our social life is made distinct. After a while our avatars acquire their own social life, through their creations and interactions with others. Their story is slightly different (but intimately entwined of course) with our RL story. If you have ever actively used more than one avatar for any length of time (as I have) you will find that you feel slightly different as each. If you have ever lost a close friend or lover from SL - the avatar stops being used or the account canceled - you will go through a (little) mourning process.
One of the people I have loved in SL has gone forever (Inthe Cosmos) - she has canceled her account having found love in RL. I will never see her again. Likewise, what joy when two other of my loves briefly popped back into SL just to tell me how they are doing (both well) - making the difference between a death and a separation!
Of course a RL death, also has a drastic impact on (most people's) social life, but it is not the whole story. In SL death, in a lesser but real sense is possible - along with the loss and mourning processes that go with it.
PS. An interesting possibility with SL is everlasting avatars - Linden will, on receipt of a valid will, transfer an avatar and its properties to a beneficiary, or inform friends of the death of the user. Exactly how crucial is the process of death and renewal to our society? Is the changing of our generations essential? What would happen if social entities never died (like institutions)? We may find out with SL!
