I'm not trying to be snarky, but I found information within 60 seconds of looking on wowhead with the search feature - on two separate links. The items and their stats are static. If you have the staff that drops from him and you get another staff, it will have the same stats. The only other option would be him dropping a potential 1hand (cannot find information on off hands/shields).
With that said, you only get to kill him one more week before SL launches, so you may as well just do it and see what you get. And if not, SL will be replacing your items for you immediately, so it's not really a loss.