Most notably, they'll look more natural: you can expect speech synchronization, skin shading and eyes that track for interesting objects (such as your finger or a bouncing ball). They won't look like today's glasses-wearing ghosts, in other words. Developers will even have the option of contributing their own apparel (including content that you have to unlock). All told, it sounds like you'll have a chance at creating a virtual self that looks and behaves more like you.