There is still one PS4 announcement to come : Level 5 game

[Aerys]

KyleeStrutt said:
The best western event to announce DQXI is the Paris Game Week, but no, a game that huge its getting its on event.

Still, fully expecting it to be on PS4.

Take a look at Square Enix E3 trailer, it would be a good event to announce it, they want to make it huge