Let's see now.... 14 slots next to the character.
We have the basic 4 armor pieces, the horse, and 4 weapon slots. Which leaves us with 5.
Looking at the placement of the boxes, it seems there's 1 extra slot for the horse, 1 new armor slot, 0 new weapon slots, and 3 separate boxes under the weapon slots.
If you look closely at the video, you can see that a cloak/robe is being added as a single item, so that's probally the new item slot.
I'm guessing horse armor for the horse slot (horse armor DLC announced?).
The 3 new slots.... unsure. Either ranged weapons or special items like barricades, ammo refill, bombs, etc.
Can't make alot out of the other menus. Perhaps pre-defined NPC variations. The last menu does really look alot like skills, but perhaps it might be tech or some sort, unsure.
tl;dr cape/robes now have a separate slot, horse armor DLC confirmed
