Major spoilers ahead. You have been warned.
Thrall's dialogue reveals that pieces of him have broken apart and that his spirit is only held together by tenuous bonds. His voice is ethereal and angry, potentially that piece of him that fuels his anger and doubt, worried that Garrosh will ruin the Horde and that King Varian deserves true orcish war once more at the gates of Stormwind.
We also learn that Thrall asks Aggra to be his lifemate, which immediately brought to mind the Jay and Silent Bob hetero-lifemate connection. Thrall, buddy, you can conjure elements to do your bidding, but you just can't summon the element of love.
Hearing Thrall rage at Garrosh and threaten Varian with unmitigated destruction in the streets of Stormwind was definitely a treat, but it will probably just be "angry Thrall piece" that is part of his fear and doubt. What a shame.
The news is already rolling out for the upcoming WoW Patch 4.2! Preview the new Firelands raid, marvel at the new legendary staff, and get the inside scoop on new quest hubs -- plus new Tier 12 armor!