Last night, during its Dragon Quest 30th Anniversary Project presentation, Square Enix was rather light on the information about the upcoming Dragon Quest XI. If you were looking information about Dragon Quest Heroes II, Dragon Quest Monsters: Joker 3, or Dragon Quest Builders, you were in luck, but DQXI was mostly incognito.
According to Gematsu, Dragon Quest creator Yuji Horii did take the stage to let fans know that Square Enix is looking to deliver the game sometime during the series' 30th anniversary year. That period is between May 27, 2016 and May 27, 2017. Horii also let fans know that the story is nearly done and the beginning of the game is playable, so all that's left is filling out the rest of the game's world.
Let's assume the worst case scenario, because frankly, it's a Dragon Quest game. Dragon Quest IX was originally confirmed in development in 2006, with a 2007 release window. That was then pushed back to 2008 and Square Enix revamped the graphics in time for the 2008 Tokyo Game Show. A new release date of March 2009 was given and the game ultimately came out in Japan on July 11, 2009. North America and Europe got DQIX exactly a year later.
Then there was the Level-5 developed Dragon Quest VIII. It was revealed by Enix (the Squaresoft merge hadn't happened yet) in 2001, postponed development in early 2002, moved over to Level-5 for development in late 2002, and then given a winter 2004 release date in Japan, which it hit. Once again, a year later, we received the game in the West.
Dragon Quest VII was the worst, with its first initial announcement happening in 1996 with a planned launch on the Nintendo 64DD. Development of that title moved to the Sony PlayStation in January 1997. Then it was delayed in late 1999 and again in early 2000. It finally released on August 26, 2000 and the Western release launched more than a year later on October 31, 2001.
You can see the picture I'm painting here. We're generally seeing a three-year gap between formal announcement and final release in Japan, with an additional year until we get the game. Dragon Quest XI was announced in July 2015, so being generous puts the game's Japanese release somewhere in 2018 given the series' track record. I expect Square Enix will roll right up to that May 27, 2017 date and cruise right on past it. Even given the idea that Dragon Quest XI hits May 27, 2017 spot-on, we're still not seeing it here until early 2018 at best (the spinoffs hover around 8-12 months in localization). More likely mid to late2018 is the magic bullet.
We'll survive of course, but Dragon Quest XI is still a far off dream, not a game you'll be playing in the near future. Temper your excitement and maybe pick up Dragon Quest VII and VIII on 3DS while you wait.