This is doable at level 60 with 3 talent points in to improved blizzard apiece.
it works as follows:
mage 1 runs around using fire blast, arcane explosion and blink to annoy as many mobs as possible without getting killed. once critical mass is achieved and the mobs are reasonably close together, hit frost nova.
mage 2 drops flamestrike followed by imp blizzard. this is a surefire way of getting the attention of the mobs off mage 1. imp blizzard slows the mob pack to a crawl.
mage 1 at this point moves behind mage 2 and prepares to drop his blizzard at the nearside edge of mage 2's blizzard. as soon as the first mob moves out of the area of mage 2's blizzard, mage 1 starts channeling.
mage 2 moves behind mage 1 and repeats step 3 until everything is dead.
Basically it's a safer method of aoe farming than running in and spamming arcane explosion. AE is a more effective method of dealing damage but it's a little too close for comfort.
Check out the talent build here
