So the interesting new talent here is "World in Flames", which gives +2-6% crit chance to flamestrike, Blast Wave, Dragon Breath, Living Bomb, Arcane Explosion and Blizzard.
So my suggestion for WotLK aoe grinding would be:
Fire Talents - 8 point(s)
# Improved Fire Blast - rank 2/2
# Incineration - rank 3/3
# World in Flames - rank 3/3
Frost Talents - 63 point(s)
# Frost Warding - rank 2/2
# Ice Floes - rank 3/3
# Ice Shards - rank 5/5
# Frostbite - rank 3/3
# Elemental Precision - rank 3/3
# Permafrost - rank 3/3
# Piercing Ice - rank 3/3
# Icy Veins - rank 1/1
# Improved Blizzard - rank 3/3
# Arctic Reach - rank 2/2
# Frost Channeling - rank 3/3
# Shatter - rank 5/5
# Cold Snap - rank 1/1
# Improved Cone of Cold - rank 3/3
# Cold as Ice - rank 2/2
# Winter's Chill - rank 3/3
# Shattered Barrier - rank 2/2
# Ice Barrier - rank 1/1
# Arctic Winds - rank 5/5
# Fingers of Frost - rank 2/2
# Summon Water Elemental - rank 1/1
# Improved Water Elemental - rank 2/3
# Chilled to the Bone - rank 5/5
(Post count not high enough to post links)
With this build you have:
Chill
15% chance for Chill to freeze
+20% chill movement reduction
65% chill effect on blizzard (1.5 sec)
+3 seconds chill duration
Damage
+11% frost damage
Winters Chill (+2-6% frost damage)
Crit
+50% crit chance on frozen targets (inc. Blizzard)
Fingers of Frost (Treats next frost spell as targets are frozen)
+100% crit damage for frost spells (inc. Blizzard)
CC
Frost Nova effect when Ice Barrier fades
Other
-20% frost nova cooldown
-13% frost spell costs
-20% Ice Barrier and Ice Block cooldowns
I do not know however if spells like Fingers of Frost only apply for one tick or full channeling progress, but I would guess it's the latter.
Thoughts?