For example you are sneaking into a fort and trying to do it without killing anyone but one guard gets too close and you are forced to kill them. Rather than leaving them on the floor for another patrolling guard to find and alarm the fort surely there should be the ability to pick up the body and hide it in a storeroom or in a dark/shadowy corner where they aren't going to be discovered.
Same scenario but rather than killing the guard, one of the perks alows you to use the helm of your sword to knock them out for 12/24 hours in game. You still need to hide body to remain unknown but you have managed to avoid killing the guard. Good for Theives guild quests where you aren't aloud too kill anyone (assuming they will behave like in Oblivion)
What about if you kill someone out in the wilderness, maybe if you had a spade you could bury them, afterall a gentleman cleans up after themselves. This could be reported in the paper (black horse courier) that 'whoever has disappeared' rather than 'whoever found dead' if you were just to leave the body in the open. It would just add an extra layer of immersion to see tha game reporting what you have done.
What about if you were to pick up a body a use it as a weapon by throwing it at a group of enemies charging at you (obviously would require strength/perk, however strength is handled in the game)
What about if you are sent to save a kidnapped child rather than having it follow you back and getting left behind because you run faster or getting stuck somewhere, what if you could simply pick them up and carry them back to their parents