Some comments on last boss in Azjol Nerub that I have read from plusheal.com forums:
People need to be moving from the spikey/rumbley earth. If all your DPS are relentlessly taking huge damage from that its gonna be a git to keep everyone up. The couple of times I've wiped on it I've pointed out to the DPS that they're doing the equivilent of standing in fire, they've fixed it and its been fine.
Prayer of mending is your biggest asset in that fight. With all the adds and swarms there's a lot of spread damage which can easily be covered by prayer of mending. Just keep renew on the tank: combined with PoM it will give you a bigger window to use some OFSR regen.
My biggest problem with the fight, assuming everyone is dodging the spikes, is dealing with the venom spitters that come out in the second and third wave of adds since I'm a priest and I can't dispel poison. Those guys are stunnable so make sure the tank and dps are watching out for them. Stun locking and killing them quickly can save you a lot of mana in this fight.
Just to echo what's been said, the spikes and pound MUST be avoided. One slip up here and there isn't the end of the world, but if people can't stay out of the way, it's gonna cause problems.
Having a shaman or hunter w/ NR Totem or MotW helps a lot.
If you have no one to clear up that poison then make sure anyone who can stun those poison spitting spiders is doing that.
We wiped once (the 1st time we went there) and never again. What I learned is that everyone must move out of the spikes and the stomp as said before.
On the poison, get a Prayer of Mending rolling, Holy Nova a couple of times to keep people up, shield lowest health player and get a hasted Prayer of Healing. That should keep everyone up while poison lasts and give you enough time to bring everyone up before boss emerges again.
More important the sheer DPS in that fight are stuns/interupts. I'm not sure which stuns/interupts work, but anything that the group can do to stop that the better. Also, staying out of the dirt and having a dedicated add-picker-upper (the little adds, like a mage to AOE or a DK) helps a ton. A "smart" group will take most of my mana for the whole encounter. A "non-smart" group can take a pot, an innervate and still wipe.
time our group ran it (I was dps at the time), we wiped 4 or 5 times and blamed it on the poison each time. Then, the final time, everyone finally realized what the spikes from the ground looked like and everyone managed to stay clear. We got him down relatively easily after that. Now, as a resto shaman, it's fairly straight forward, but I'm guessing that the spikes are the biggest obstacle for most groups.
On every attempt except the last, I had severe OOM issues from needing to spam heals non-stop due to massive party damage. Once everyone figured out that they shouldn't be standing in places where they'd get hurt (me included, there), the fight went much better.
Such as: if you see spikes on the ground, MOVE. And if you see the boss casting Pound, RUN AWAY.
No, this fight is about positioning as much as DPS and survivability. If your DPS can't move out of the way of the very obvious ground effect that deals a large amount of damage, and can't understand that killing the venomcasters (or whatever they're called) that mass poison the group, then that is entirely their problem.