Yeah but the way Todd was going on about it in Jan, the Shopkeeps wife knew you killed her husband...but gave you the quest to acquire an artifact from a theif...like really, I just jabbed your Husband in the face with a dagger and your giving me a quest to acquire an artifact that was precious to him :facepalm:
Yes, I remember reading this as well, but I'm sure they have been testing the way this plays out a lot since January.
I remember reading that if you killed the quest giver's sister, wife, husband, etc., then the quest would reflect it in some way, like it might be harder for you to convince them, or they would be angry about it. (if it was known that you killed them - I imagine if it was a stealth kill, nobody knows)
Hopefully they have refined this aspect. At any rate, keep in mind it still seems to be a big improvement over Oblivion, where you could kill someone and the relatives wouldn't even bat an eye when they ask you, "And what's going on with you? Look at the muscles on you!"