Since I run healer main and am working on tank (Glad at 26 so far) I figured I'd stop in to note that people are jerks to all classes. As a healer I saw plenty of angry tanks assault DPS and Healers for their own shortcomings. I also saw (even more) DPS assault tanks for the same.

As a tank I don't get nearly as much abuse from healers as I expected. Probably because I start off letting people know this isn't my main class and invite critique. However, I get a massive amount of rude commentary from DPS again when they ignore the numbered and marked order or pull additional groups from other places via bad tab rotation.

Playing tank is making me a better healer because I have a better grasp on how alpha strikes effect tanks, how annoying it is to have your interrupt on GCD (Seriously, wtf?) and how frustrating it is to see a snoozing mob wake up because of a pugilist and head straight for the THM. As a result, I take aggro and head to the tank now (on non-AoE centric mobs) so they can easy flash the aggro back. I place my fairies more carefully to make sure the tank gets regen benefits as often as possible, etc etc.

Side note: I'm really enjoying tanking so far. I do a dungeon 3-4 times until I feel it's understood, then grind to the next dungeon and do the same.