As posted earlier today by bigfootmike, Square-Enix has a new countdown clock up on their Japanese site.

While the mystery will be revealed in approximately five days, the internet may have some clues. Members of the Neogaf forums believe this countdown to be related to Lord of Vermillion, a popular arcade game that Square-Enix operates in Japan. While the game is over a year old and no home version or port looks likely, Square-Enix did register Lord of Arcana with the U.S. Patent and Trademark office.

Anything at this point is speculation, but the art styles of the game and the teaser site do look similar, and the URL for the countdown does not mention anything Final Fantasy-related. Time will tell, but it doesn't look like this is news will mean much to non-Japanese gamers.

Source: Neogaf Forums, Siliconera, Lord of Vermillion Site