The Buff: Like your hearthstone or the hour-long Valentines debuff, it keeps counting down while you're logged out. So don't expect to log and continue as a pirate the next day. Also, it does not do anything other than change your physical appearance--including hair, skin, face, and clothes--and shifting form removes it. Your weapons and race remain the same.
Dustfire in the Middle
My Druid, Breaking It Down
[Yes, that's my cute little Netherwhelp. No, it's not her permanent companion. That one will be announced in November.]