So with the NX officially pegged for March 2017 and Zelda U officially announced for it - it only seems a matter of time that some 3rd parties will start confirming titles for the platform.

By launching in March 2017 - it probably won't get any sports games or Call of Duty at its launch. It may not even necessarily get the annualized installments of Skylanders, Just Dance, Disney Infinity, or Lego Dimensions. However, it would be in Nintendo's best interest to allow third parties to begin to confirm 2017 NX ports by E3 this year, even if they can't necessarily show or demo NX gameplay. 

My gut-feel here would be that Square would be the first on the scene with something like Dragon Quest 11, Kingdom Hearts, or even FFXV.

I'm gona say Either Dragon Quest XI or Project CARS for some reason...

Probably Dragon Quest XI since they hinted at it during its reveal and said they want to release it on the series' 30th anniversary which runs from 27th May 2016 - 27 May 2017, Good bet it will be a NX launch title.

Something from Square Enix.

I'll say Monster Hunter...

Even for as bad as the Project Cars WiiU fallout ended up being - Slightly Mad was certainly more committed to the WiiU than many other devs. I wouldn't be surprised to see it actually. Namco-Bandai and Slightly Mad will probably want to repush the game for VR anyway - so why not have it for NX too I guess?

Dragon Quest XI. The game is slated for 2017 too.

Yeah, I'm going to say Dragon Quest XI. But it could be anything, any game releasing early next year...

Destiny II

I'd say dragon quest Xi, but if I did a smartly dressed Japanese man is likely to rock up and tell me that they haven't officially unveiled nx yet. I'll say no more