I'd like to bring this one up so far since I think it's nice to update it.
Since the Smash trailer, we knew Pit being shown early had some kind of sign of things to come. Here's the current things we have for the KI universe. I'll be using Sakurai's photos for reference.
1: So far we know Pit has 2 new moves: Upperdash Arm and Guardian Orbitars for Side-B and Down-B respectively.
-The Upperdash Arm was shown in the trailer and multiple "Pic of the Day" photos. Based on the photo and Sakurai's comment shown on September 6, it seems like the Upperdash Arm will have Super Armor frames. We do not know if powerful hits will stop the move yet.
-The Guardian Orbitars were shown in the Developer Direct and in 1 "pic of the day" photo (shown on July 6). It is unconfirmed about the move's properties, or if it will be able to reflect projectiles so far. They do have added patterns on the shields though.
2: A new KI stage, featuring the Reset Bomb Forest (chapter 11 in KIU) was shown. So far we have 3 photos, shown on July 23, August 1, and August 27 respectively. They show that the stage will change over time
3: The first new item revealed, which is from Kid Icarus: Uprising. The X-bomb, which was shown to us on August 16.
And that's all the stuff we got in just nearly 4 months since the Smash trailer. But what more KI universe stuff is to come we wonder?