My thoughts on PVP itemization is that you would benefit from the stuff you found in PVE. There should be a vendor that sells you PVP items according to some point system. This point system would be calculated on the stats of your gear, or in other words gear value (gearscore). This gear value would be the currency to buy those items.
So if you invested time to PVE and found nice gear for your character. Then you want to do PVP you could buy PVP gear from the vendor. Why we need PVP gear? To balance the stats to a reasonable level, probably need to replace stats like CHD to something else etc. We could also just have the stats automatically balanced for PVP but it might be confusing, when you enter arena your stats are way different..
Having 2 sets of gear would of course need a sort of switch so you could turn on the PVP gear.
Anyways this would still show the gear progression in PVP which for many must be an important part in Diablo games. This would also make people want to farm more loot to be better at PVP.