Just a thread where you can announce if you'll be gone from the site. It would be helpful if you explained why you'll be one or at least let us know for how long so we know not to delete your account, posts, etc.
If you randomly disappear but you're account is still intact please come here to explain what happened, so we know you're just not starting to drift away and eventually become completely inactive. We wouldn't want to delete your account if you have to leave for a valid reason ^^;
If you truly are going to leave the site for good, let the Administrator or any of the Moderators know directly so they can deal with it rather than posting it here.