Greetings,there's even a nifty screenshot of the GM response.
Thank you for contacting the World of Warcraft Game Master Department.
The Macabre Marionette is a temporary item meant to be removed once the Day of the Dead holiday was over. There is currently an issue where the pet will remain on a character after the holiday.
Once this issue is resolved, all players will no longer have the Macabre Marionette.
Please accept our apologies for any frustration this may have caused.
-source (towards the very bottom of the comment page)
until blizzard releases an official statement, though, there is still hope that the marionette will be made into a real vanity pet (i'm getting flashbacks of Pinocchio - 'you're a real boy, now! you're a real boy, now!').
two new pets, the lich and the panda, were just released. and as cool and awesome as they are, i think i'll be spending more time with my cute skeleton friend. gotta enjoy it while it lasts.