“Trick or Treat”

While we have had a number of odder hints over the last few days including a large cast, “it is long”, “More than one Announcement” and “What in the World is Inside that Box of Mayo?”. While I love guessing games I somehow doubt I will be getting any closer to the actual truth about this announcement with Trick or Treat being the latest hint. The closest thing that comes to mind is the Umineko no Naku Koro ni anime series, as it had a long title (and 26 episodes long), large cast, involved the Schrödinger Cat (To some extent – thus the box) and involves a character who is obsessive about witchcraft and Halloween.

With the exception of this… any ideas?