This is the current plan, as described by Olivia Grace of Wowhead, of how PvP gear will work in Warlords:
This is how PvP gear is going to work in Warlords of Draenor - it will have one lower item level for PvE content such as questing, dungeons or raids, as well as a higher item level for PvP. You can see that this piece's item level is 660 in PvE, and 690 in PvP.The PvP/PvE gear split is getting excessively complicated. At this point, maybe we should take a step back and ask ourselves: Is this a problem worth solving?
Is it really important for PvE gear to be mechanically different from PvP gear?
The origins of the split comes from TBC. At that time, PvE was strict-progression, while PvP was seasonal. Thus as new PvP seasons appeared, it became easier for people to get gear from PvP, even if they were stuck on hard bosses in PvE.
But now PvE is seasonal, just like PvP. When a new raid comes out, everyone moves to the new raid and gets new gear. It is far less likely that someone will get "stuck" and have to resort to PvP to gear up.
There will be about 5 levels of PvE gear: LFR, Normal, Heroic, Mythic, Mythic-Warforged. Three levels of PvP gear, set at about LFR, Heroic, and Mythic-Warforged would be good, especially if the costs and requirements for that gear is set to match PvE.
With PvP and PvE gear being set at roughly the same level, people could more easily cross over and dip into both activities. I have very fond memories of working in Alterac Valley to get my [The Unstoppable Force], even though I was primarily a PvE player. However, since the gear-split, my desire and inclination to build multiple sets has really fallen.
Is it really so terrible that top PvP players have good enough gear to do high end PvE? Or vice-versa?
Really, the only items that caused significant imbalance were trinkets. Perhaps only trinkets would work differently in PvP and PvE. As for Best-In-Slot, the people who chase Best-In-Slot will always be crazy and go to extreme lengths. Is it really worth forcing the rest of us to navigate these complexities?
Basically, I just don't think it is worth jumping through hoops to maintain the PvP-PvE gear split any more. PvE has changed from progression to seasonal, matching PvP. Using the same gear for both activities would allow people to participate in both activities more easily. People could get away with maintaining one gear set per specialization.
The PvP-PvE gear split is complexity that we don't need anymore. As such, the game would be better off without it.