Just a thought. I re-spec'd to frost and have been trying to AoE. It's really fun!!! I'm not very good yet, but I'm having a blast.
That being said, I was wondering if anyone has ever used a tank to grab all the bad guys into one spot, and then have the tank focus on a ranged mob (i.e. spellcaster or of the sort). Then, you can start your Blizzard "pull" on the group since they should be nicely packed. The melee will come after you, and you can AoE/kite them to death. All the meanwhile, the tank will keep focus on ranged mobs, and hopefully hold their aggro since you won't be damaging them after the initial Blizzard (they would also be standing next to the tank anyway, so it would be easy for the tank to identify them). Would that work?
Also, would that ever work in an instance? Rest of party focus on ranged while mage takes out all melee?
Just a thought. I haven't had the guts to ask a group to let me try this yet :)