It's definitely painful. What I was doing with my shaman healer was trying to bait the DK out in the open - they're usually stupid agressive when they approach and we'll AOE earthbind him. Purge his AMS and then go to town on him. If he gets cleansed, lay another castsequenced earthbind, then open up. My healer dual specced to Elemental and baited him/thunderstormed him and then earthbind him to take him out. The whole thing is to avoid him in the first place - it's only a 10 yard spell.

But yeah if your team get's frozen it's pretty damned annoying.