PvP would be a lot more interesting and I think a bit more fun if every PvP arena had their own bonuses and penalties assigned to them. We have tons of different arena settings we play in but none of them have special bonuses and penalties assigned to them like increased/decreased healing, no dispels allowed, half damage on mass attacks/heals, extra damage on 1v1 attacks, etc.
When we play some bosses in the game often they have their own rules for playing them, I think we could do that for PvP.