Some key points that tie this into being a Xenoblade sequel:
- The item orbs are back. Can be seen in a couple of scenes, and one gets picked up.
- The battle system is relatively the same as in Xenoblade, as shown in the last trailer. Auras are still around, as is the art system and action icon.
- Look at the flowing lights running around the mechs. Remind you of anything? Yeah, Mechon and Faces. Exactly the same.
- The shulk lookalike in the first trailer.
- The ending of Xenoblade - go out and find new worlds. They do that. Their ship crashes (the monolithsoft promo art is obviously this, going by the two moons). They build a civilization.
Those are my thoughts anyway, feel free to discuss.
I have a feeling they haven't announced the title yet because they want Xenoblade 2 to be a big reveal in terms of the name.