I've been playing since late Morrowind and I love making characters in ES. I like to try out concepts and see how they work. While I can't say I've made everything (might be impossible to do so) I think I've covered the bases pretty well. I rarely play a pure role (pure Combat or Magic or Stealth) because skill use in other skill groups helps enhance your main focus. (magic enhancing Combat, stealth enhancing Combat, Magic enhancing Stealth. I prefer Combat/Magic myself)
Stealth enhancing Magic tends to be lacking in this regard and as the topic title suggests, I'm referring to being able to sneak attack with spells. True, we can be stealthy mages, but the concept doesn't hold up very well in combat compared to sticking a blade in someone's back or an arrow between the eyes from ten paces away. It seems to me that we should be able to do the same thing with Magic, Destruction in particular. Who's to say we can't slide up to a lack-witted marauder, put a finger against his spleen and proceed to fry him with 10,000 volts? He would never know what hit him. Can't a fireball, lobbed from a safe distance, take a group unawares, reducing them to so much pencil lead?
As far as I've been able to reason by myself, implementing this within Skyrim would not unbalance the system. (using Oblivion as a guide) While spells have a higher damage output than weapons, they do come with a cost to magika and are generally slower than attacking with weapons. Knowing how and when to use spells is key and sneak attacking with them can greatly enhance them.
In conclusion and tl;dr: Sneak attacking with spells is cool. It's also, I believe, an interesting concept to play a character who never touches a weapon. Well, if you're still reading, thank you for sticking with me this far. Skyrim looks like an awesome game so far and I'm very pleased with what Bethesda promises with it. All I can say is that it's going to be a VERY long wait until November rolls around.