I hope light comes from actual lanterns/torches this time instead of lame invisible light source crap.
I agree fully with that, and on true darkness. If you're in a dungeon, there are no light sources around, and the player is not carrying a torch or using nighteye, it should be dark, as in, can't see [censored] level of darkness, like what you get in Oblivion with mods like Darker Dungeons installed. If you're worried about not being able to see clearly, that's what torches are for.
Being able to put out, or even relight, static light sources would be nice too, though. It would go pretty well with stealth gameplay. To go along with this, I'd say that NPCs should put out their lights when they go to sleep at night, because most people don't sleep with their lights on in real life. And if the game is already designed to support this sort of thing, it would seem foolish to not reflect it in the game too.