Quote of the evening last night: "we need war druids cant tank". (Of course, two druids proceeded to tank, presumably confusing this particular group member.)
What defines a 'good' tank? What do you look for when selecting which group member should take on the onerous duty of being hit a lot? As a tank, what do you look for in a group?
Having spent much of my time until level 60 in PuGs, I have something of a fear of tanking. Despite being a feral druid (for the most part), my experiences with random people have been universally dismal. To give you some idea, the best run I'd had for a long time was the Stockades, an instance which is loathed by many players.
From the tank's point of view, it really helps to have group members who understand -- and listen. Those who realise it takes time to build up aggro, and don't rush in immediately with killer DPS. Those who realise that sometimes the squishies shouldn't do all the pulling. Those who appreciate the problems of adds -- or too much to handle -- and yell if they're in trouble. I've encountered everything from crazy DPS shadow priests to tanking mages, and most of it puts me off tanking with strangers -- but it's a dirty job, and someone's gotta do it.