No point to this post but to tell my story.
My friend's a holy pally, fairly well geared too. I'm levelling a druid on his server to play, and when I was 65 he was helping me with some quests in coilfang reservoir. So we're off to underbog, with the idea being him healing, me tanking "I think I'm high enough that I should tank this time" (since he tanked in ST and I healed...him in his healing gear me in my feral gear). So we find 3 DPS, figure CC can be forgotten about, and we're off!
Well, my friend turned out to be able to pretty much hold aggro better than me, and since he had about 5k armor more and less than 1K health less than me, we figured he should tank. Looked in LFG for a healer for a while, everyone was feral, shadow, or prot, so I just asked him "why don't you tank and heal?"
He tanked without losing aggro unless I growled, kept everyone alive, and still pulled 35% of the DPS, topping the charts. I know he's a 70, but still...he did everything better than me when I'm doing one thing at a time.
Oh well, I'll be off-tanking his kara group in a week, so I can't complain.