The only problem with NPCs sneak attacking us is there isn't a feasible way (at least not that I can think of) for NPCs to get "sneak checked" on a PC as the game doesn't know what you the person playing the game can see. They can't logically do any attack from behind either because if you are facing the enemy and turn around to separate yourself from him and he shoots you you knew he was there.
As for the actual topic it should definitely be in as that would be a ton of fun. If they do implement this they better give me a tower shield so I can rush them.
Check NPC sneak skill versus player sneak skill, trying avoid line of sight of player in AI settings will help sneak behind player, trying avoid close combat and changing position after ranged attack in combat style settings.
Player skilled in sneak is hard to be ambushed because he understood how to ambush.
Others can use torches to reduce enemy sneak skill in certain radius around.
Light and detect life spells will be much more useful for mages I believe.