My 83 paladin has a 316 avg item level, reforged everything that didn't have spirit to get spirit, and can easily run a normal dungeon without stopping to drink more than once or twice if there's a big pull with no cc.
I ran Stonecore the other day and the level 82 DK tank didn't use CC on a single pull, just charged in and tried to tank everything. I kept the group alive all the way to Ozuruk. We did have one wipe when nobody killed the sentry and he pulled 3 additional groups onto us. Even then I kept everyone up until the 3rd group showed up. After we regrouped the tank pulled the last group before Ozuruk with one of the large brutish guys instead of just pulling the brute separate. I was low on mana (around 20%) after that pull and before I could even sit down to drink the tank ran straight into Ozuruk.
At this point I did everything I could to keep the tank up. I drank a mana pot, popped divine plea, and popped my BE racial to get as much mana as possible. Then the DK decided he was just going to run back into Ozuruk during every single Shatter as he was shouting in party chat "HEAL ME!". I had 1% mana by the 3rd Shatter, had already used Word of Glory and LoH and could do nothing but sit there and watch him die as he's still shouting "HEAL ME!". After he dies he starts ripping on me for being a lousy healer.
WTF?!?! How can someone that stupid have the mental capacity to even turn on their computer, let alone make it to level 82.