My concern with PVP is one I have had for a while as have others; the impossibility of balancing things.
Entire kits would need to be removed from PvP in order to deal with possible shenanigans and stuff you just can't get around. Biotic charge would be gone because it is effectively a sync attack, as would Shadow Strike. Wallbang powers would need to be removed as well as powers that ragdoll hard else they'd need to be super easy to dodge. Lash in particular would be great for the lols but stagger power and troll-ability of Lash with pierce in PvP would be hellish.
Blade armor would become the ultimate troll power since you could get up in someone's face and know for a fact that if they start meleeing you they will kill themselves.
The list goes on. To have PvP you need to either severely nerf these powers or remove them completely and doing that would be tantamount to removing Vanguards, Batarians, etc.
So take your pick, incredibly nerfed or removed. You could have different stats for the different types so that lash can't pierce no matter what in the PvP version, or Biotic Charge is a skill shot along with all powers, so on and so forth, but I don't know how well they would balance such things. I'd be incredibly surprised if they did it successfully especially if they let PvE fall by the wayside.