I recently implemented an attachment feature for the animation system. It allows an object to be attached to any bone of any other object, and is how I intend to implement weapons, hats and other decorations that a character might have. These were created in Softimage, which has a great model-referencing system that allows me to composite scenes to make new assets that are based on or interact with existing assets.
The other thing this video shows is the new additive animation feature, which for instance allows a character to overlay an animation on top of other animations. This is used to make the recoil of the weapon affect the character. Additive animations are a great way to add life to a character because they stack with each other in a way that makes sense visually, allowing you to create small bits of animation that don't need to be replicated in everything else being applied to the character.
These animations are still just placeholders, I know they aren't that great.. I'm mainly interested in making the tech work at this point and will revisit the animations themselves when I have a better idea of exactly what the system will support.