The way we do it in our guild is that we have the Pally along with a shaman or another healer on the MT. Hodirs Frozen Blows hits hard so we have to keep the Mt up at all times. We then have myelf a Holy Priest keeping the rest of the raid up. Becuase of the fact I have gone into the empower renew talent I HOT up each person and POM myself. With that said and done the only thing the pally and other healer needs to worry about is keeping the tank up and moving away from the cave ins and getting on the mounds when Flash Freeze happens.
*Remember, you always need to keep moving otherwise you will get the debuff that stacks. Once you pass 4 debuffs the damage you take becomes quite a bit and it is hard to get rid off.