Do we know if the player and NPC's will be able to have different shapes and sizes? This is something that has always been lacking in TES games and adds a huge sense of immersion and creativity.

Already asked many times. There is a hint about being able to choose a body dimension. We don't know for sure yet.

I'd say it's more than a hint. At the bottom of page 51 in the Game Informer magazine article there is a caption for a screenshot that reads:

"Facial and body features are entirely customizable."

I assume at the very least that means the ability to change body size.

Ah, well I hope it turns out to be true and that NPC's get variety!