A quest in which one team works against the other. Maybe both teams have a tent across the map and have to guard some npcs or something. Lots of npc bad guys would spawn from a cave in the middle and attack both teams evenly. If you really want you can brave the higher ground above the cave and fight through a medium amount of baddies to hassle the other team with some PVP. Make it so both teams always get exp but the winner gets the items!
I grow tired of hearing the "THIS ISN'T WoW YOU NUB!" nay saying too. Lets face it. Players fighting other players peaks the interest of many. And it is a big audience to cater to if you wish it.
Isn't it about time to include ONE pvp quest?