What do we know?
We know it looks bananas.
We know the UI resembles that of Xenoblade, the battle system looks similar as well with the action bar, color coded abilities, even the Warning banner came over. The symbol in the middle of the action bar looks like the chain-attack symbol from Xenoblade. Another connection.
There's a time-of-day clock, like in Xenoblade, suggesting a full 24 hour day/night-cycle.
We know it has at least 4 player online co-op. There's a text chat window and there are solo scenes, two player scenes and 4 player scenes. Though it looks like you can roam the world at your whim and not be tied to the other guys.
Remember Nintendo patenting massively singleplayer online game a while ago? Yea, I guess that would fit ...
Like in Xenoblade, the world looks huge with weirdly shaped rock formations, sprawling landscapes, huge waterfalls, a big see, open fields and HUGE FREAKING MONSTERS!
Your character also has guns. Swords and guns.
You can target specific body parts and seemingly cut them off strategically.
Also, there's mechs. You can pilot a mech, with a jet pack. Oh and it also transforms into a bike. WHAT!?
There are scenes without any UI so I guess you could move all the elements to the GamePad or they fade out automatically.
Oh that guy at the end? Looks pretty much like HD Shulk.
I'm extremely excited for this game! Like can't wait gotta have now-excited!