While I have not done this encounter on Heroic, I did just finish it this morning on normal. My first attempt was a wipe because of the spike damage. However on attempt two, it was a trivial encounter like Hungerfen. All I did was DPS when he was up, when he was buried, I just walked backwards with everyone on follow killing the adds. As long as I was moving, no spike damage. Killing the adds that were casters were more of a problem than anything else as they would just stand there and cast while I was moving. But 8 DOT's took care of them.

This is exactly how I killed Hungerfen. Just walk backwards and DOT and beat on him with the paladin.

Paladin 4xdruid group.