There will be no open world PVP or "PKing" and PVP will always be an after thought,
It's not going to be open world, but it sure isn't going to be an afterthought- There were plans in the 2.0 doc for a large-scale pvp system where the outcome of which would open up access to or impact certain Pve content, such that people who like pvp can do it and those who don't want to don't have to, and yet these two sides of the coin can interact with each other indirectly.

Issue with pvp is it's hard to balance it alongside pve content.
It seems like they're already taking that into some consideration- for instance, conjurer/white mage is considerably more capable from a combat standpoint than WHM was in FFXI.