Every pre-Cata nightmare I thought would occur has so far happened. Here's what I've had happen so far:
Blackrock Caverns normal: Tank pulls entire room with Rom'Ogg and we wipe. On 3rd boss, tank refuses to move him into the fire even after we're screaming for 30 seconds to do so. Tank taunts back adds on final boss after we clearly explain they should be kited. He gets MS debuff and eventually dies.
Throne of the Tides normal. Random PUG DPS DK dies 10 times in the dungeon. Tank gets one-shot by 2nd boss 3 times. We end up killing the boss with myself and a hunter pinging aggro back and forth and kiting while taking melees and praying we don't get crit and one shot. Tank refuses to move 3rd boss out of poison cloud.
Vortex Pinnacle: Tank doesn't pull dragon out of the heal void zone, moonkin has to go bear and taunt it out. On the large tol'vir packs, the tank wipes us by refuses to LoS and pull the healers out of the anti-magic zone. We take 5 minutes trying to explain the concept of LoS to this person but they can't get it. Tank cusses out moonkin who bear taunts the 2nd healer mob and LoS's it so it can be CC'd. Tank dies on Assad and says, "This is such bullshit why am I dying in a dungeon."
Lost City of Tolvir: Group wipes once on first boss b/c 3 people die standing in the ground spikes. We replaced 3 DPS in a row. Tank dies 3 times on trash pulls before begrudlingly letting the DPS CC a couple targets. Big man tank syndrome is cool, right?
But the one good thing is that all these little wrath babies who leave dungeons after 1 wipe or who don't know what LoS means or what a kill order is will get NO GEAR.