The title does a pretty good job to describe what this updated demo is about.
-Trackpad movement Onward style (switch between this and teleport with the grip button on the left controller).
-Tutorial at the beginning of the demo.
-Quick Inventory, you will never be stuck again by loosing a quest item to the dreaded floor.
-Slightly rotated hands for added realism.
-Loot is kind of shiny now.
-New mechanics for grabbing and you can make a fist by keeping the trigger pressed.
-A lot more but I don't remember every improvements ;)