Apart from larger-scale Company Vs. Company battles, we prolly won't be seeing much open-world PvP in FFXIV, seeing how it relates more to the lore and storytelling. And i partly hope SE won't make open-world, as it is quite a difficult concept to uphold and satisfy large numbers of players.

There never seems to be a satisfying level of roaming NPC monsters in correlation to PC opponents. Nothing is more frustrating in an open-world PvP game, than not being able to opt out of PvP when you just want to explore or do quests in certain areas. And what it comes to pure PvP, nothing is more annoying than a bunch of low-lvl mobs running behind you casting random debuffs, when you try to challenge a worthy opponent face-to-face.