I think they need to put a level limit on what players you can kill and also place an xp gain on killing players to entice pvp on pvp servers but on higher levels.
There should be a 30 level limit on what you can kill but the xp quality will be gray for someone 20 levels below you and someone with the same level as you as quality xp. Also with this system they can add more spontaneous world pvp on lower level zones.
Who knows maybe they can make the gurubashi arena more grand? They can make it a twice a week event with 800g reward, with 100 people tryin to get it!
Who knows?? I'd elaborate and tell more but there's point in telling something that has no approval yet :P