Lack of pvp? huh?
You mean rest of empty map areas with basic material nodes, right?
All you need is one map exclusive to pvp faction vs faction, ditch DT currency (so you could buy mats at the auction house from pve players), using same currency as everyone else)), have pvp exclusive rank system, have gear with pvp exclusive stats, which can be bought for gold ( "pvp ranked", so non pvp players won't be able to buy unless they rank-up in pvp), have exclusive pvp reward system which will not effect pve in any way, all materials which needed for pve should be obtainable in pve and not behind pvp