Dragon Quest X has been in development for 6 years according to a now-deleted tweet by former Square Enix employee Takehko Hoashi, Andriasang reports.
Hoashi also stated the Wii version of the game will not be released until 2012, putting the game in development for nearly seven years.
However the Dragon Quest franchise is known for lengthy developments, with 2009's Dragon Quest IX being released an entire five years after its predecessor.
If Hoashi is right, then it's likely Dragon Quest X was being developed in parallel with Dragon Quest IX.
It has been confirmed that Dragon Quest X will include cross-platform play and online group-play.