Did this one last week the hard part we found was positioning the ice blocks properly and breaking them at the right time. They have to be close enough to the tanks that the can both be switching off and breaking stacks each Ice Block.
Having tanks who are able to charge made this easier for our group (Bear and warrior).
We had both Ice Blocks being dropped by her head one 10 yards behind the other when the first was not yet down.
Assigning one DPS to the blocks and leaving the rest to DPS the boss helps to make the timing for breaking the blocks more controllable and any one decent DPS and can easily handle the Ice Blocks alone.
Hope that helps.
Addon Author: What's Next? - AllPlates - Sudoku - Death Clock - Super Loot