So DQXI was just officially announced. It's coming to both PS4 and 3DS as I expected. I just didn't see them moving away from Nintendo's handhelds, but Yuji Horii had already confirmed it was coming to a home console, so this seemed like the most logical conclusion.
They're two very different games with different development teams. The PS4 version runs on Unreal Engine 4 and looks amazing, but I'm a little worried about too much of DQX seeping in. The town footage they've shown could've easily been mistaken for an MMO with how massive it was. Not having any NPCs in it obviously wasn't helping. They didn't show off the battle system, so there's a chance it'll play like DQX.
The 3DS version was weird. The top screen shows the game in 3D, and you can move the camera all the way from the top-down to the behind-the-back position. The bottom screen displays the game as it were made for the SNES. They did show off the battle system in this one, which was a tradition turn-based battle system.
The PS4 version will be my first choice, but I'll likely end up playing both.