According to a Gematsu translation of a Game Jouhou report, Dragon Quest creator Yuji Horii delivered the news at the recent Nico Nico Super Conference 3. Horii offered no solid information on the game, simply describing it as the "next" Dragon Quest, before moving on to other topics.
Before fans of classic, turn-based, Japanese roleplaying games get too excited, keep in mind that we have no word on when this new game might appear, nor if it will be available outside of Japan. Dragon Quest X, the most recent entry in the franchise, offers Japanese fans a massively multiplayer online world, but has yet to see release outside of its native land.
Dragon Quest publisher Square Enix refused to comment on Horii's statement.