I believe that open world PVP is the fundamental essence of any MMORPG, which unfortunately in recent years has been lost. I think it would be a great idea to allow open world PVP and that you have to fight for Raids, farm zones, etc. Something like Lineage 2 but with factions.
This game makes me very excited and this is one of the reasons, it has returned my faith to the MMORPG, I hope I can enjoy it.