It depends solely on who it is and how the killing of him was.
In my opinion, the staff is an item to give a newbie a chance when fighting a more experienced player. Thus it's low morale of an experienced puke player to use a staff and it should be looted. For the same reason, I leave the staves after killing newbies.
After an overkill, I prefer leaving the staff as I feel bad after overkilling. To make it short - if the dead enemy was entitled to the advantage of a staff, i.e. he being a much worse player than I, I leave it. Otherwise I loot it.
It is clearly not in the spirit of the game to leave behind artifacts of the enemy for easy retrieval. Several people claim they act on roleplaying motivations when they leave it behind because it's clearly not an item you can use yourself. I dont understand that reasoning; roleplaying a darkie has to be about serving the master, whos major interest in staves is their destruction! Not a selfish motivation to consider whether items are of use to you or not.
Finally, leaving behind items to help the enemy recover from death faster, to allow you fight him sooner, is clearly not permissible by either mume rules or Tolkien's universe.
Comments?