How about a system like wow, Pvp Battlegrounds?
New maps, maybe slow down the characters movement speed, the win / lose thing... how about... we do add a type of "Dress up" gear into the game? Like the gear in warcraft but fit for lions / wolves to make them look cooler? Like when you get honor points on wow, you can get better gear, but ours would be without stats, just for looks. Nothing that can be traded though.
We could have arenas, but no way to heal urself unless you kill an opponent and get a healing item?
Just random ideas. : )