This system was the reason I actually liked being a healer in pvp. Keep your tank targeted while you could use cc or a dmg attack on an enemy attacking you from behind. Some may say it is not necessary or that it takes away the skill required to heal in pvp, but from my personal experience it just made it easier for me to use my all of my given abilities. If you can use your abilities on defensive and offensive targets without dual targeting, then I would call that skill. If you make good use of a dual targeting system to use abilities on defensive and offensive targets, I would also call that skill. Supporting this system!