Just wanted to throw my tips in here for mixed groups.

I parked my guys on the left wall just as you enter, spacing my guys out about 10 yards so that only one person gets spiked at a time. You won't pull the boss until you get nearly within melee range, so don't be afraid to walk onto the platform and take time setting up. Put your most resilient alt closest to the ramp you came down to be able to take a couple hits if you don't pick up an add right away (for me, shaman or boomkin). I don't park too far from the door so that my tank doesn't have much running to do to pick up adds (your taunts my still be on cooldown when adds start appearing faster on later phases).

If you have a shaman, definitely use nature resist and cleasning totems, as already suggested. If you park along the wall, just turn the shammy when casting totems so that they are all piled up on the wall behind the team and you don't have to worry about any of them getting agg by new adds.

Be sure to avoid the Pound attack by Anub'Arak. You just need to move off to the side a little, as it is just a forward cone attack, and not a full frontal attack, and make sure he's either not pointed at the rest of the group at all times, or kept at a safe distance that it will not reach them (only like a 10-15 yard range). He's seems to have a tendency to use Pound very quickly after coming back up from underground, watch for it. Other than that, his insect swarm ability will do some damage to the group, but it's a rather weak attack to begin with and won't kill anyone by itself.

As adds appear, obviously give priority to the elites, but keep whatever taunts you need on the non-elites as well. With pali tank, I just keep popping a consecrate in front of the group and then move to pull the elites when they arrive. The consecrate pulls agg from most of the non-elites that appear.

I also just eat the spikes and throw a Greater Heal at them once they land. Obviously try to avoid the spikes with the tank. Ironically, its the tank that takes the least damage on this fight for me. Anub hardly hurts him (avoiding Pound); it's the adds that will really test you. If you can keep everything on the tank and remove poison very quickly, then mana on the healer shouldn't be too much of an issue. If mana is your biggest pain point, you might want to just gear up elsewhere a bit more first to bump up your +hit/spellpower/mp5.