Target the Healer!! has been said time after time in randoms with varying degrees of success, but the emphasis 90% of the time when selecting targets in PvP should be a healing class. Addons help in discerning which opposing player to target. Experience also plays a big part if you are familiar with what exactly a healing class looks like. And this brings me to my point. As a sometime hybrid Holy Priest healer I feel like I am a walking bullseye with my chakra animation. The only other example would be a druid in tree form but they are not in that state all the time. Take a look at it?